I think 30 days is reasonable and should be left as is, for active managers, and shouldn't be changed. Sometimes I get multiple requests in the same family line all at once. Someone starts clicking on merges of every family member -often because of uploaded gedcoms. Often with erroneous data.
Each one needs to be checked and researched prior to merging. Sometimes they have different parents/spouses/spouse's wrong, missing, etc. LN. Particularly if they are part of a project.
This takes time. And if I'm away, and not able to do the research, to approve, query, reject, confirm, then in 14 days the merges would be completed, and left in a mess.
Some have mutliple PMs as noted, and queries go between them. Or someone you want to confirm with, happens to be away themselves, and isn't seeing your message.
I do agree that inactive PM's, probably shouldn't have a say in it!!! Hey, if someone is inactive for 2, 3 years or more...
I'd rather see a method of removing someone as a PM is they are totally inactive.
But I MUCH prefer the 30 day window for merge approval.