There are no open source for rk3528, as I understand. Please anybody correct me if I'm wrong!
There are unofficial Armbian ports; Almost everything works except the usual quirky stuff that TV boxes have.
It's the first time I hear of RK3528
Has been out for a while; Android 13 TV boxes that use it are super cheap: 15~20€ (during promo sales) for 4GB/32GB.
Good enough for Klipper or similar stuff.