Kotlin Coding capabilities with the new WFF

Question

We developed Watchfaces for a health app that show several information (graphical curves, different values like Insulin BG value, Insulin on Board, Carb on Board, ...) One watchface can be tuned without any coding from final user (all the information, images, font are included into a zip file to be shown within a "customized Watchface" (convertion between zip file content and watchface layout is done by code to tune the layout, visibility, text color, positionning, size, font according to bitmaps, font and a structured json file included)...

I just discovered the new WFF format, but I understood reading quickly the documentation that it's completly "locked"...

So my question is: is it possible, with Kotlin code (included into the associated App installed within the Watch) to update the elements included into a WFF watchface (replace an image by another, tune the color of text according to a value received by the phone, update text according to received values change position x, y, or width, heigh of a text, of an image, change a font, include a custom graph to show colored curves...

Currently I didn't try anything, I just received a warning about scared users who lost their favorite watchfaces after buying their latest Watch (Wear OS 5)

Just as an example, within watch, one watchface is installed (named "Custom WF") and user can send all these watchfaces (and much more) from the main app, they can tune their own WF...