Chroma Keying in v9

Description

It appears chroma keying was removed in V9, I can downgrade my project to v8 but would rather understand the intended way to chroma key in v9? I do not have enough memory to up the framebuffer to a 24 bit ARGB format.

What MCU/Processor/Board and compiler are you using?

STM32L4R9ZG

What LVGL version are you using?

V9.1

What do you want to achieve?

chroma key/ transparent background icons

What have you tried so far?

looked everywhere for a 1 bit alpha chromakey in the master, only mentions are of older versions of LVGL