We have seen in the past some threads that have been locked by their respective OPs because they did not care about conversations ending without a conclusion. A certain member that declared his account dead stating he would never return, did make a comeback and when questioned as to whether the creator of the account was in control, he locked the thread.
As for setting limits (and defining parameters), as it is all part of modifying the thread locking process I cannot support it. Others will post their views on the matter and some will support it but I cannot endorse it.
Th3 OP will be the one to set a limit, which means the OP of such thread won't be really affected apart from not getting enough replies , or reasonable discussion in some case.
On a normal day Topic can be locked by a mod if it deserves to be just like you've mentioned, that doesn'trequire consent even if such OP think other wise.
Imo, the only detrimental part Is that conversations can be cut-off midway without any reasonable discussion yet.