I can say for have TWRP we needs someone that have experience in treble A/B devices and with vbmeta.img.
The S10/S10+ have the layout of a Treble A/B device with boot.img without ramdisk because is in root folder etc but he dont use it (like A/B treble is disabled)
I allready compiled a TWRP for the S10+ but he cant boot because of vbmeta.img that blocks the recovery with the error message Recovery: Verifing footer failed (6). Thats means Samsung added AVB checks for recovery partition in vbmeta.img.
Now on phones with fastboot is that disabled in 3 mins but on Samsung phones not because we dont have fastboot.
Now for boot TWRP on the S10/S10+ is there someone needed that knows how to edit vbmeta.img for allow the recovery to boot or we need to find out how to resign and add the footer back to custom recovery.
When someone have an idea how to edit vbmeta.img or resign and readd the footer back in custom recovery let me know that because for flash magisk this time is twrp needed and dont works anymore like on S9/N9 with patch boot.img and then flash it with odin because boot.img dont have any ramdisk inside.
What i found are the tools from Samsung byself in his firmware odin tar where in it is a signing key and some tools that i dont know how to use (for get the tools open the ap file from odin tar and in it is a meta-data folder with a zip. zip password ist fota12345)