I use FABDVD and I have it installed on a 2020 Mac mini i3 quad core 32gb DDR4 HyperX , i5 MacBook Air 2017 8gb with Samsung evo 9700 SSD and a 2012 Mac mini 16gb DDR3 HyperX 256gb HyperX and all 3 machines give up doing a avi to MP4, the 2020 gets about 3/4 way through before it stops.
I also own a MacBook Pro m1 and out of curiosity I converted same file .avi 500mb to .mp4 4.5gb/ATMOS etc.. and it actually finished where as other machines gave up 1/2 to 3/4 through. The converting took around an 50mins to do.