I'm sorry, I don't know why I suddenly thought you where on Linux all of a sudden lol, must've been tired yesterday, or atleast mildly confused somehow
There's no deluge2 installer on windows, but if wanted there's an unofficial deluge2 windows installer by petersasi if interested testing, also the newest version provided is actually kindly built and supplied by fmar, which both has windows 7 and 10 versions provided, here links for both if interested:
Unofficial Deluge 2 for Windows 7 + 10 - Curtesy of fmar.
Unofficial Deluge 2.0.x for Windows installer - Curtesy of petersasi.
I tested previously on the files tab, as thought originally you asked for that, when mentioned "a filter on filenames", but could be torrent filenames too, so pretty sure I tested it in main torrent list also, maybe you need select a torrent first or mouse-click an empy place in torrent list to change focus to there. Granted was on deluge2, and also I could remember wrong(not at my computer now). Not optimal I know, but all there is, and I couldn't find no plugin for this neither upon quick search I did yesterday. Deluge2 has additionally that ctrl+F searchbar for the main torrent-list, which I don't think is on deluge1 but as said, could be wrong about that.