So...
There was I working on my Sublime Python installation when it came the time to install a new build system.
All was going fair and square until the moment I thought: "wait a minute!"
Well, I got a little carried away and a day and a half of pain and suffering later, here am I with a new build system for MSX Basic Dignified and MSX Basic in general on Sublime 3 (only on MacOS for now, sorry)
MSX Badig Build is on the same repo as MSX Sublime Syntax.
It converts the opened source to a chosen folder and file (settings via an .ini), open openMSX, load a save state (obligatory), mount the folder as a disk, turn throttle on (to speed things up, optional) and run the converted basic program.
To end the test just close openMSX.
It is not instantaneous but the whole thing is faster and maybe more usable than I thought it would be.
My initial ideia was to check if there was already a running instance of openMSX to avoid opening it every time but so far I couldn't figure out how to do it.
It is working like a charm on my computer but it has a lot of moving parts and I have no way to test it on a different environment. If someone is interested, please take a look, I would love some feedback.
Cheers.