Adding Ability levels through triggers

Is it possible to add ability levels through triggers? For my save code I have a number that dictates what level the ability that was added is. I know there is a way to detect what level the ability is but as far as I can see there is no way to actually add levels to the ability. Also I doubt the hero-learn ability skill would work either because all spells are added through the action unit- add ability. I imagine there is a way to do this im sort of brain dead at the moment, so is there any way to do this?

I have the sneaking suspicion that if you add the same ability twice it would increase the level... but in truth I have no idea.

Also I can't set it up so each level is a different spell. Each spell needs to be saved, and I only have 676 (the amount of combinations AA, AB etc. can give) savable spells, and I have close to 115 custom spells. Considering that each spell has 6-10 levels each, there isn't nearly enough spots to do that.

Well, GUI Trigger wise, I don't think its possible, although in 1.17, there's a new trigger that allows you to change the level of abilities for units.

Care to elaborate? Such as when 1.17 comes out, and whatnot. Also what do you mean "GUI trigger wise". Does that mean its only available in JASS for 1.17? Or it will be in GUI for 1.17 but only JASS for 1.16?

i think is just as you said. adding twice the ability.

No it isn't, you actually can't level up abilities without using the "Order unit to learn ability" action, however as HexenLordX said, in 1.17 there are the actions Increase ability level for unit, Decrease ability level for unit and Set level of ability for unit which work for hero and unit abilities