If you're shooting with a 50mm f4 lens on FF / 135 to match:
Angle of view
Perspective distortion
"Compression"
Depth of field
On MFT (for ease of maths) you need to use a lens twice as wide (25mm) and open up the lens two whole stops (f2)
If you don't adjust the aperture there is a two stop difference between FF / 135 and MFT.
That's it.
Have you read Steve Yedlin's excellent articles on matching blur across formats?
https://www.yedlin.net/NerdyFilmTechStuff/MatchLensBlur.html