iPhone Slo-motion workflow?

I have some footage shot at 4k @ 120fps on iPhone 16 Pro. (Prores isn’t possible at 120fps, so I’m stuck with HEIC). Mac OS Finder shows three files for each clip - IMG_2714 (13GB), and IMG_E2714 (4GB), along with IMG_2714.AAE

The E clip will slow-mo play at 30fps, but the normally named one plays real-time in FInder & QT Player - but since it has 4x the data, I’m assuming the E clip is re-encoded, and comparing. matching frames, it definitely has less detail.

I’ve tried a few things with compressor and Resolve, but so far nothing that gives me access to all the frames in the original clip within Flame.

Has anyone done this with maintaining the highest-quality in their workflow?