I suggest that adding someone to your blocklist exempts them from recieving your heal&buffs [and you from recieving theirs]. There are several reasons to this, but the main issues are:
1st: Bots profit from your heals&buffs. You basically help bots if you cast Blessing or put down heals near them and they run into it e.g.
2nd: Griefplay. People who like to griefplay others by ruining their setups [e.g. running in and out of your Counterspell or eating up your heal tiles to prevent you from killing monsters] would be unable to trigger your setups anymore.
3rd: Rude behaviour. People who are spreading their useless buffs across the party or think that they don’t have to spend $$$ on potions by just using up all the Ein Sof/Heal tiles for themselves won’t be able to continue their mistreatment of others.
Last but not least: Setup issues. Not every class can make use of all buffs. By blocking someone, you wouldn’t recieve their buffs anymore, keeping your bufflimit in check while actively cooperating.
I believe the social features of the game are actually great and help people to advance together. However, there are some people who don’t want to help and disturb ± everyones gaming experience, and I honestly don’t understand why I can’t prevent them from doing so. The least the game needs is to lose more playerbase due to bots& bad-mannered players.
If not via block, it could also be resolved via a “cooperation”-tag which works similar to block but just blocks the skill issues.