Alley can do the loop trim and cropping, and converting to DXV for you also on Windows
You just need to export your footage to a format Alley can read. Prores is supported on both mac and win.
Then load it up into Alley, move the end markers on the timeline to the points you'd like, hit Convert on the bottom, then on the next page Set Size to Custom, and your desired clip size, and set Scaling to Fill.
Hit Queue button on the bottom, and wait a minute for the finished file.
Yes, Balaton is a great place, hopefully the restrictions will be lifted when the nice weather arrives.