Why not just add the recipe to the base heating tower tech instead?

just don't use it until gleba if you don't want to

The liquid heating tower tech has the heating tower tech as a prerequisite. And is researched by crafting a heating tower.

So, why? You achieve the same by unlocking the liquid heating tower recipe with the heating tower tech without adding a new tech that effectively does nothing.

i considered gating it behind the heating tower before, but decided against it because:
1) it doubles as a flare stack
2) freedom to decide how you wish to play the game at any stage
3) the tech while does nothing by itself, it has interactions with some other mods

I see, I'd still suggest cleaning it up a bit by using:
if mods["mod-that-interacts"] then
Conditionals.

I'll leave it at that, just made no sense in isolation.