You mention several devices in you posts … both A5s are now legacy … the work done on FM radio for /e/OS can be checked out here Files · v1-s · e / os / android_packages_apps_FMRadio · GitLab. The link is intended to point to Android 12 (S).
It seems that the current progress (that is having FM radio “system installed” on some devices including my Moto G7 Power - ocean – listening now thanks to /e/ devs 
) will not include any legacy devices.
As regards third party installable apps, I think the previous thread covers the ground. I never succeeded, nor to build FM Radio into Android 11(R) – when attempting use of GitHub - LineageOS/android_packages_apps_FMRadio at lineage-18.0.