Consider Taking Zinc Every Time You Travel

Why do you think that?

They sound exclusive because they are valuable for the same reasons but if one gets you most of the gains, it is unlikely the other one is then also worthwhile at the new margin. (If you have a working belt, do you really need suspenders?) It seems like going by all of the details you list, a N95 is strictly superior to zinc lozenges:

1. The weak research on zinc is not an issue for masks, which have evidence from COVID now, in addition to the fundamental mechanistic plausibility of masks filtering particles of airborne illness that would be infecting your mouth.
2. Masks are even more broad spectrum: presumably zinc's mechanism works for only some viruses/bacteria, but masks physically filter out everything.
3. You raise a lot of alarming points about getting the wrong kind of zinc, or using it wrong, or side-effects from such large amounts of nutritionally-unnecessary zinc, suggesting that even if it does work in experiments, it won't work for you. Masks, in contrast, seem a lot more foolproof. (I don't need to worry about 'depleting copper' when I wear my P100 mask.)
4. Masks are much cheaper: following the first link I noticed, I see a bottle for 30 lozenges at $9; a N95 mask is <$1 and good indefinitely, so has paid for itself after 4 pills' equivalent. If you've gone through 3 or 4 packs, then you have paid for a better P100 mask which you can then use everywhere else too.
5. You describe the experience as being physically unpleasant: taking a large pill (itself very difficult for quite a few people) and holding it and letting the nasty zinc coat your mouth. I'm not a fan of masks, but their discomfort and inconvenience is much less than zinc sounds like.

So, it sounds like masks buy you most of the feasible risk reduction at a small cost, and then use of zinc buys you a reduction in a now-small-absolute risk at a high relative cost; it sounds unlikely that the zinc is worthwhile. Further, as you do not mention already masking all of the time, or using even better masks (like someone would who is serious about not getting infected rather than merely complying with norms), that implies you do not put that high a value on not being infected and thus any benefits from reductions, making it even more unlikely that the small benefit of zinc justifies its costs.

N95s are, at a rough guess, significantly more effective, and have the massive benefit of not being something you put in your body, which can go wrong a lot of ways (the claimed loss of taste side effect, or just general mild dysfunction)

It’s not just personal, in general taking medical advice from reviews in areas you’re not expert in, especially when you haven’t read the review, is probably not great, and as described elsewhere this really doesn’t feel like the sort of thing that would work (compare to magnesium for headache / low energy, which definitely biologically seems somewhat reasonable, although I’m still somewhat iffy on it). That together with personal anecdotes being the sort of thing that Chinese traditional medicine and energy therapy has by bucketloads, and my experience with meta analyses like that regularly falling apart (5-httlpr had a stronger meta analysis with p=0.0001 and four hundred studies, most of which were positive, and then just got executed by a large well done study, https://slatestarcodex.com/2019/05/07/5-httlpr-a-pointed-review/) and priming, with thousands of studies and meta analyses that was also fake and I don’t mean this insultingly because I’ve done this in the past too ... a lot ... smh ... but if you didn’t look closely at the study, it’s probably one of the tens of thousands of bad studies and bad meta analyses that get published so much because so many people want to do them). So I’m pretty confident that the current evidence base for zinc shouldn’t be enough to conclude anything,. And neutral on if it works. But it probably doesn’t because most treatments don’t.

I looked for preregistered trials and found this in 2020 - https://bmjopen.bmj.com/content/10/1/e031662.abstract - preregistration massively helps with both publication bias, post analysis bias, study design, and many other tricks one can do. It found

Results There was no difference in the recovery rate between zinc and placebo participants during the 10-day follow-up (rate ratio for zinc vs placebo=0.68, 95% CI 0.42 to 1.08; p=0.10). The recovery rate for the two groups was similar during the 5-day intervention, but for 2 days after the end of zinc/placebo use, the zinc participants recovered significantly slower compared with the placebo participants (p=0.003). In the zinc group, 37% did not report adverse effects, the corresponding proportion being 69% in the placebo group.

Conclusions A commercially available zinc acetate lozenge was not effective in treating the common cold when instructed to be used for 5 days after the first symptoms. Taste has been a common problem in previous zinc lozenge trials, but a third of zinc participants did not complain of any adverse effects. More research is needed to evaluate the characteristics of zinc lozenges that may be clinically efficacious before zinc lozenges can be widely promoted for common cold treatment.

Which I find much, much more persuasive. Also note the side effect rate and the (admittedly, subgroup, so it is probably meaningless) lower rate of recovery for takers.

During these 3 months, I've gone through one or two packs of 30 lozenges each, not sure. Yeah, I was sick a lot and worried, wondering if I am getting sick or not, even more. I suspect that Life Extension peppermint lozenges hurt my teeth worse than anything else I regularly consume. Perhaps they're made of sugar? I haven't checked. As for helping with common cold, I have no idea if they are helping. Maybe, slightly. In the beginning I thought that maybe I am noticing some positive effect, but it could easily be placebo. I also have a hunch that maybe they help with throat symptoms but not with nose symptoms.

Also wouldn’t the constant swallowing and cycling of mucus make any coating wash off?

It will wash off over time, but you take several a day.

(I can’t see the starch or cellulose in pill binders mixed with zinc “physically coating” the throat, because solid matter tends to go down it)