Using 10.5 Pro ........
Not been happy with iMovie macOS, but no need for final cut pro X. Been searching for a quick and easy to use video app, also with fast finalizing, and that´s what is LumaFusion. Already very happy now, works like a charme on iPad Pro. But also (did not notice a difference yet, but I am only doing 1080p in the moment) very fine on iPad 2017.
May be a selectable number of tracks would be nice, so it´s up to user and the used hardware what he can do with it.
Thanks for the title idea, I will try and post a result here when done, as I think that more users are running out of tracks sometimes.
I have also bought a IPad Pro 10,5 because of LumaFusion (maybe they should make some kind of cooperation with apple like a discount of 10% for LumaFusion users) and I'm very happy with this app, especially because of the super-ultimative cheap pricing (other PC Software is only from 80 EUR or more avaible and the thieves from AdobePP take 20 EUR very month + a super complicated application).
Regarding your idea, I really like this. Very often I was thinking about having more than 3 tracks next to each other - but for what? In the end it was always enough for me to take a trimmed soundclip for the sections i want and the 2nd track line for the next track (transition sound) and the 3rd trackline for additional sounds like waterfalls or lightning sounds.
And at this last point I totally agree with you - if I have a sequence with a music track and I wanna add more than 2 sounds (like bird sounds, rain, lightning, speaking myself, and so on) I'm coming into trouble, because there are not enough sound track lines.
-> Please let the user chose how many sound and video tracks he wants to use (also for video, because sometimes I want to fade in several title lines like an layer, and its not enough).
BTW: the smileys in this forum are awful