Thanks for your reply.descryption (viewing) not possible with TWRP, and encryption not compatible with custom ROM/MODs. actual encryption/decrypion process cannot be done on demand.. only once based on flags and data formatting.
I found that it makes no sense to do encrytion while on TWRP.
However, what the difference if I patch only Magisk to the Original FW to achieve root, use an app to remove bloat/system apps, and I still can do encrytion by stock FW itself. Does it still safe?