Inspiration needs a rework, lol. Nerfing Inspiration into Sorcery didn't help either.
Okay so, the keystones are pretty good, I don't have much beef there except Glacial Augment is really hard to fit on virtually every champ. it's the runes after that, short of the cosmic insight line, those runes are excellent. the hextech flash/biscuits/stopwatch line or boots/futures market/minion dematerializer? The stopwatch is pretty good, don't get me wrong, and magical footwear is an excellent choice for most any support, but really the options available are awful and super niche.
I have more than just a complaint, I have a potential solution. So Inspiration's whole thing is gettin' jiggy with it, breakin' the rules with stuff that's clever, right? It shouldn't be locked down in the same way as the other rune pages are, you should be able to say, choose to swap out one rune line with the rune line of the secondary tree you're running. The idea being you get to have 3 lines of secondary runes in your secondary tree, and only two in your primary. That way I could just skip the future's market rune line.
If not that, then be able to choose two runes from one of the lines in Inspiration. I'd be a lot happier if I could take both Insight and Approach Velocity, or stopwatch and biscuits, instead of being forced to take Future's Market or Magical Footwear.
barring that, you could buff hextech flashtraption and minion demateralizer/future's market. They are weak af.