I wouldn't recommend HCQ for folk who are exposed to some vaccinated people who are doing fine, unless they fill ill.
Yeah, don't want to over-do it (especially if it isn't necessary) and you are certainly in a different position than most in the amount of precautions that would be helpful. There are a number of us like myself who work among scores (if not hundreds) of employees and guests in a given work day - so upping the zinc, Vit C, D, etc. - and maybe just using the Ivermectin (monthly) sounds like one route to boost defenses then. If it seems like there is a significantly higher incidence of people feeling ill after getting vaccinated in our high-people-traffic jobs (though I have heard a few stories already) then maybe some of us can (also) try low doses of HCG.