I just tried the free version and I wonder if you could address some these issues before I decide whether to buy. The first one by far the biggest problem I found, and it's also the main reason I haven't bought the program yet, since I'm looking for something that can work with subtitles without causing problems.
Subtitles often cause problems with cut segments (x265, mkv). Since everything I edit has subtitles, it happens A LOT. So I troubleshooted this myself and found out that if a subtitle line starts earler than the cut point, it usually causes the output to look glitchy or makes the program freeze at "Now Splitting The Sequence" part.
To easily reproduce, make an SRT subtitle (just save as .txt and rename to .srt) with an entry like this:
1
00:00:05,000 --> 00:00:10,000
Blah-blah-blah.
Merge it into any mkv video, and try cutting that video at 6 seconds (again, notice that the subtitle line starts at 5 sec). The program will either get stuck at 100% of "Now Splitting The Sequence...", or it'll output a segment with an extra second of buggy/empty video footage.
The easiest solution for this would probably be to demux and re-edit the subtitles to make sure that none of them go beyond the cut points. So in this case, 00:00:05,000 --> 00:00:10,000 would become 00:00:06,000 --> 00:00:10,000, and so on.
Another issue I noticed is more like a missing feature than a bug. It's that you can't set up Select Streams in the Media panel before adding the file to the timeline.
The reason it's important is because the program seems to have issues with some streams. Some of them take long to load and make the program freeze for quite a while before you can toggle them off in Select Streams. Some of them are unsupported or don't even seem to load, like some TrueHD Atmos streams I tested. Would be great if I could disable the unsupported audio streams and unnecessary subtitles, as well as set up which streams to cut and use for preview BEFORE I drag the file from the media panel and loaded it into the timeline.