I don’t see a good reason to remove ‘Abstain’ votes from quorum. The sole purpose is to count participation without forcing a stance, as many in the thread have pointed out. Abstaining is like delegating to your peers and I think it is better to keep it as part of quorum. Quorum should reflect engagement.
The current design is such that if you don’t want your vote to count towards quorum, you vote against, if you want it to vote towards quorum but don’t want to support directly, you vote abstain. That’s better.
Also, changing cost is a thing.