Indeed. Once you press the S or any other, the search selection will be completely reset. Which is a bit annoying.
But you can indeed use a work around by adding
&sort=seeders&order=desc behind the url, or replace seeders with whatever you wish to sort on. Or change desc to asc .
So create the selection you wish, press search and then add the work around.
Maybe when we have time we can have a look into this (at least the programmers) but for now I guess this is an easy option.
Thanks for the heads up