Thanks for feedback! That limit is there because the whole file is held in memory for editing, and long files got heavy. But good point, nobody has asked about it before.
I'll try different solution in next update to raise the limit.
And a new Split Mode is coming in the next update, to detect and export multiple slices at once. Could be handy for field recordings too.
EDIT: Found the solution. Next version will support up to 60min audio files/recordings.