@Desais Sorry to tag you sir, i only do when it is an important matter like reporting bugs and all that and you are the moist active moderator here.
I'm one of the good reader of replies, especially on my own topics, and some topics just needs a one strait answer so after a short or long discussion i finally got an answer i needed an answer that could help people any reader of that topic.
So here is my suggestions;
on the reactions i request to be added another icon to mark reply as the best and once reply is marked as the best the topic should be auto locked to admin will lock it manually if he see the need.
OR you can form any other form if request to lock the topic.