Captain Sim wrote on Jun 4^th, 2020 at 2:55pm:

Kees wrote on Jun 3rd, 2020 at 8:45pm: I hope you will reconsider this option. Well, you are asking us to re-build the entire 767 code from scratch (which is years of work) just to make it fit better one particular homepit needs. The answer is no, sorry.

So, I suspect that the main need isn't to necessarily write those values directly, but instead get a fast performance so that rotary inputs can change values quickly.  I haven't gotten to actually try this out yet (hopefully this weekend), but I wonder if the slow response is because it is calling LUA scripts to access LVARS as opposed to a more performant environment like C++/SimConnect.  Anyway, I do not know how to access LVARS outsite of a Lua script (yet), but hopefully there is a way...