Mov->m4v encoder setting

Hi forum experts

i make a lot of gifs. my issue is that the format i post them to has a 10m cap. recently i found out that i can covert them to m4v which results in a massively smaller file size, so i can make my gifs longer/more colors/less dithered etc.

i would like to keep my process adobe native BUT i am having trouble with getting from MOV  (my output from AE) to M4V.

so, I am trying to convert a MOV to m4v. It can be vid only. Right now the issue i am running into is that the 'system preset' mpeg4 settings force aspect ratio on me (i want it to match source) and they won't let me do so in the export settings (its grayed out). i have gotten PRETTY close to what i want with the attached set up (see pic) but the final quality is still well below what i get with my current workflow (MOV > CONVERTIO.CO if under 100m, if over 100m then MOV>PS to gif (to get under 100) then to CONVERTIO)

settings image

https://i.imgur.com/T1EEPmN.png

output using these settings (i had to convert the m4v encoder output to a gif to get it to load, it kept erroring)

https://i.imgur.com/yHyibZ5.mp4

output usings my current workflow MOV-convertio

New York Dj GIF by The Lot Radio - Find & Share on GIPHY

ANYWAY all thoughts appreciated, apologies for any blatant noobness