That matches pretty closely with my experience. The main reason that I still sometimes shoot with the LR iOS camera is that I very often post-process photos with the Mastin Labs film emulation presets, and they work much better with RAW files—in part because I can adjust WB and tint, which is important to get the best look.
The also have profiles that work with JPGs/HEIC files, though, and I've increasingly been shooting with the built-in iPhone camera and then just applying those profiles in the Photos iOS app. The results are often pretty good.