As the Qlik tab is being deprecated, the Pre/ and Post-script is no longer available (nor advisable). That leaves us with a gap compared to previous functionality, since this was a way to add some of the useful stuff like a Qlik Sense derived calendar etc.
I appreciate that you aim for a more "front-end" agnostic tool, and i guess it would be a major task to satisfy all our front-end specific requirements.
An alternative for filling this gap, would be, if you could simply dump the Qlik loadscript into a txt-file, like you could on the old Qlik-tab. As i see it, you cannot dump a loadscript in the semantic layer, without also loading a Qlik-app? Then we could simply build our own Qlik apps (which I prefer anyway), but with the benefits of a fully documented datamodel from TX.
When that is done, we simply need a way to trigger a Qlik Sense task, whenever the data is ready in TX.