Rendering Large 16bit ProRes limitations

I am working in some large canvas sizes for HD and 4K video wall productions. My last project was set up at 14250 x 2222 and I was pre rendering using both 16bit PNG/ Trillions and also ProRes 422HQ / trillions. I was able to produce a 10 minute video using this workflow. My current project is set up at 13040 x 2700 and I am noticing that my ProRes prerenders set to 16 bit / Trillions are not recognized by after effects when the project is set to 16 bit. When I switch the project settings to 8 bit the prerenders appear. Furthermore, when I try and render out the prerendered 16bit Prores it immediately fails. After doing some tests, it seems that there is a limit to the vertical size at which I can work at. I can get files rendered at 16 bit ProRes to appear up to about 2200 pixels high. As I mentioned, my previous project was set at 2222 pixels high and the 16 bit ProRes renders appeared. My question are - Does anybody know the exact specs on size limitations when using ProRes. Also, am I smart to use 16 Bit PNG sequences as my prerenders??? I have been using these for their quality, ability to render an alpha, and small file size, but they take forever to render and are also slow to update in the timeline (I use quarter res ProRes proxys until render time). I started using the ProRes pre renders to expedite the renders and timeline updating. My current project is set up at 13040x2700 23.976 fps and I am using a combination of footage shot with canon mark3 in H264, ProRes footage, Large still images, vector files, and a slew of effects in AE. It seems that ProRes wont work this time at 2700 pixels high in 16 bit.... unless I am overlooking a setting somewhere.

thank you.

Thank you for the reply Walter. I hear you on using img sequences. I tried the ProRes thing to help with render times. I will go back to img sequences. I typically use 16bit PNG sequences (rendered with Trillions or course) as my primary go to pre render format for projects of this size. Do you recommend an alliterative to PNG Sequence. Keep in mind that These files are enormous if I use TIFF or anything uncompressed at 13000 pixels wide. I appreciate your help and input.

What image sequence would you prefer going with at 8 bit when dealing with a large AE canvas? PNG has been my typical workflow but if you can suggest a better image sequence for 8 bit that renders faster than png and refreshes quicker in the timeline I'm all ears. Thanks again.

Thank you Walter. I have used photo jpeg in the past. To be honest I never saw to many issues with using pjeg as final prerender layers before except on gradients. I am using a lot of gradients in my color / design on this project but I think I'll keep using PNG for now. It was nice when the ProRes miraculaously worked at 14400x2222 as it increased my renders significantly.
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