https://www.youtube.com/watch?v=p7pX2MJRV70

Inserting an energy cube into an energy matrix converts energy at 1/10th of the ratio of normal, both in and out. Filling/Emptying an ultimate energy cube gives 5 MRF instead of 50 MRF when directly in the matrix, however when connected to input via cable, the ratio is 1:1. Using this, I could easily take 5 MRF from the matrix to fill an ultimate cube entirely, then fill 50 MRF back into it.

I tested this briefly on 9.8.3 to see if I could reproduce it to see if this is still and issue in 1.15 or if it got fixed in the parts that got rewrote so far, but I was unable to reproduce it in either version.

Unable to reproduce this either.