I did not experience this kind of issue but to make sure you will receive your token in a campaign, monitor the spreadsheet and incase there is a user who try to us your bct name you can contact the manager through telegram or pm him in this forum. You cannot tell each and every campaign about this issue because there is a lot of campaigns here and as you said it is very tiring. Good thing you made this topic.
Sometimes, some users can get through with it even if you always check the spreadsheet for those cheaters trying to steal your tokens. This almost happened to me, when at the first week of the campaign that I joined, I already see that someone used my profile and I reported it then during the last 2 weeks of the campaign, someone used it again. Good thing I always check telegram spreadsheet after checking signature sheet.