I want my Roaches to be able to move while burrowed which implies that the talent "Tunneling Claw" is researched.
I removed ALL requirements I could find and tried many other stuff around, nothing seems to work.
What am I -again- missing? -.-

set the burrowed roaches speed to 1.406 in the data editor.

Lol, it was indeed that easy.
Close topic, solved.

Not really an explanation on why the upgrade is not happening but that will work.

I explained it to him in the chatroom, but I'll explain it here:

If you look at the tunneling claws upgrade in the data editor it looks like this:


As you can see, the upgrade adds 1.4062 to the speed of roach (burrowed). Then if you look at the roach (borrowed) speed you notice that it is 0, so the upgrade changes the speed of a burrowed roach from 0 to 1.4062. So if you just set the roach (burrowed) speed to 1.4062 it has the same effect.

I think he meant you didn't really teach me how to actually make the upgrade researched by default.

I actually want to know how to make the upgrade researched instead of applying its effect independently on units.
Please help?

Really you shouldn't be trying to make the upgrade researched anyway. Applying it yourself is the same thing.

As to why this does not work it is because you need to research an upgrade by using an ability, there are requirements on them yes but they still need to be researched.

So the only way to make an upgrade researched is either to have the player to literally research it in-game or to modify directly the stats of units to apply the effects of the upgrade itself?
There's not even a way to research it via triggers or something?

You can probably do it via triggers but I think you would need the unit that has the upgrade ability. Why would you not just set it in the data editor?