I like the search tool on mlpol, it's quite useful for finding specific names and the like. The only problems I really have with it is that it only works currently for the active threads. In addition, the archived threads never have replies linked, making navigation even more difficult. If it's not too much to ask, is there any potential we could see these things updated in the future?
The reason you can't currently search the Archives is that the Archives was an barebone addition we made for the current codebase so we could have some form of archive.
We are working on rewriting the entire code for mlpol.net and we're planning on making the archive, among other functions, more userfriendly. It is uncertain when the new codebase will be complete but we are aiming for bringing a better user experience on all devices (*cough* mobile *cough*) and bring useful functions for users, janitors and moderators. So it is in the works, I'm just not sure when it will be completed.