[Kamil Iwanowicz] “Any thoughts ;)?”
Yes. There is no single format that will look the same in every player. If someone came up with a format or technique that did that he/she would be rich and win a bunch of technical awards.
The only thing that one could do is make a version that will look correct on a specific VOD service on a specific OS on a specific browser. Or in an offline case a specific media player with identical settings that you have. This isn’t really feasible if you need to make, let’s say, 2 services x 2 OS x 4 browsers = 16 unique versions of one file for a single web commercial.
I’m not trying to discourage your testing but there’s a reason this is unsolvable as of now. Because it actually is.