Hiya
I’ve looked through topics tagged with “post” but couldn’t see anything about this, and I think I’ve searched the meta…my basic question is…
Why are the default post settings as they are? e.g. a minimum post length of 20, topic title 15 etc…is this to present instant messenger style “Yeah” responses? Have people experimented with these settings?
This is exactly it! 
I’ve brought those limits down some, the default numbers can be too much and be arbitrary thresholds for typing.
The idea of having limits to prevent conversations being one sentence at a time back and forth does make sense in theory, but if a site is setup with default settings and the administrators aren’t interested in listening to any feedback about possible changes that can be annoying.
If the team was going to consider changing any of the default limits I would vote those be reduced to about 75% of current limits or so (meaning default of 15 characters minimum post instead of 20).
There are other options of the chat channels also for chat communication can be better for that, while posts are mainly for official proclamations that need more characters.
Thanks all for the replies!