Hello @marty_mcfly and welcome to the forum!
Actually, minute got suspend/s2idle to work with a monolithic kernel on RK3588. See this IRC log: 2025-10-23.log
Sources are here: Reform / MNT Reform Linux Kernel Development Tools · GitLab
So it works in principle. Now one has to find out what makes this not work with a modular kernel.
At collabora, Sebastian Reichel is fixing suspend/resume issues. See for example here: Making sure you're not a bot!
So work is being done and with the monolithic kernel having working suspend and resume, anybody from the community could help find out what the missing bits are. 