May be worth an PR upstream at source.mnt.re?! 
@significantalgae i just found out that reform-hw-setup more often than not is failing on my RK3588 classic reform as well:
Aug 13 08:02:07 reform systemd[1]: Starting reform-hw-setup.service - MNT Reform Hardware Defaults Setup...
Aug 13 08:02:08 reform reform-hw-setup[851]: Simple mixer control 'Playback',0
Aug 13 08:02:08 reform reform-hw-setup[851]: Capabilities: volume
Aug 13 08:02:08 reform reform-hw-setup[851]: Playback channels: Front Left - Front Right
Aug 13 08:02:08 reform reform-hw-setup[851]: Capture channels: Front Left - Front Right
Aug 13 08:02:08 reform reform-hw-setup[851]: Limits: 0 - 255
Aug 13 08:02:08 reform reform-hw-setup[851]: Front Left: 255 [100%] [0.00dB]
Aug 13 08:02:08 reform reform-hw-setup[851]: Front Right: 255 [100%] [0.00dB]
Aug 13 08:02:08 reform reform-hw-setup[857]: Simple mixer control 'Left Output Mixer PCM',0
Aug 13 08:02:08 reform reform-hw-setup[857]: Capabilities: pswitch pswitch-joined
Aug 13 08:02:08 reform reform-hw-setup[857]: Playback channels: Mono
Aug 13 08:02:08 reform reform-hw-setup[857]: Mono: Playback [on]
Aug 13 08:02:08 reform reform-hw-setup[858]: Simple mixer control 'Right Output Mixer PCM',0
Aug 13 08:02:08 reform reform-hw-setup[858]: Capabilities: pswitch pswitch-joined
Aug 13 08:02:08 reform reform-hw-setup[858]: Playback channels: Mono
Aug 13 08:02:08 reform reform-hw-setup[858]: Mono: Playback [on]
Aug 13 08:02:08 reform reform-hw-setup[860]: Simple mixer control 'Left Input Mixer Boost',0
Aug 13 08:02:08 reform reform-hw-setup[860]: Capabilities: pswitch pswitch-joined
Aug 13 08:02:08 reform reform-hw-setup[860]: Playback channels: Mono
Aug 13 08:02:08 reform reform-hw-setup[860]: Mono: Playback [on]
Aug 13 08:02:08 reform systemd[1]: reform-hw-setup.service: Deactivated successfully.
Aug 13 08:02:08 reform systemd[1]: Finished reform-hw-setup.service - MNT Reform Hardware Defaults Setup.
-- Boot 8539fa111abe449f850a8f0ad6bfa183 --
Aug 13 09:10:53 reform systemd[1]: Starting reform-hw-setup.service - MNT Reform Hardware Defaults Setup...
Aug 13 09:10:54 reform reform-hw-setup[857]: amixer: Unable to find simple control 'Playback',0
Aug 13 09:10:54 reform systemd[1]: reform-hw-setup.service: Main process exited, code=exited, status=1/FAILURE
Aug 13 09:10:54 reform systemd[1]: reform-hw-setup.service: Failed with result 'exit-code'.
Aug 13 09:10:54 reform systemd[1]: Failed to start reform-hw-setup.service - MNT Reform Hardware Defaults Setup.
-- Boot 615ba078426c47039589c04068701fd1 --
Aug 14 07:30:55 reform systemd[1]: Starting reform-hw-setup.service - MNT Reform Hardware Defaults Setup...
Aug 14 07:30:56 reform reform-hw-setup[925]: amixer: Unable to find simple control 'Playback',0
Aug 14 07:30:56 reform systemd[1]: reform-hw-setup.service: Main process exited, code=exited, status=1/FAILURE
Aug 14 07:30:56 reform systemd[1]: reform-hw-setup.service: Failed with result 'exit-code'.
Aug 14 07:30:56 reform systemd[1]: Failed to start reform-hw-setup.service - MNT Reform Hardware Defaults Setup.
Are these similar to the errors you have seen? internal speakers work for me even when the unit fails though