I have not looked at SysEx messages for a long time, and I feel your pain in V1, maybe V2 will help. I feel a dedicated module for the Akai fire would be a good addition to VCV Rack, it does seem logical, and as the controller is reasonably priced and is a good bridge between the virtual and the physical.
A scripting language may be possible as @Aria_Salvatrice has embedded JS into a plugin : Experimenting with QuickJS in my plugin outside of VCV-Prototype
I am open to collaborating in any form, feel free to DM me.