Meka is nice, since you need armor and the burst heal helps. Cool thing about support alchemist is halfway through you can decide "fuck it I'm going carry", like if you see no one efficiently farming the jungle and not TPing to empty lanes to farm them, aka your carry is a fucktard. Can also jungle semi efficiently for xp/gold if there's nothing else to do, just stack shit and acid spray it+ulti. If you don't have ulti yet it takes a while and isn't particularily efficient but still works out. With ulti 1 and like 2-3points in acid spray you can start taking the ancients which most likely your carry wouldn't be getting yet, so that's very nice.
And yeah the hero is a pretty solid support, even though he mostly only have one skill as a support early on, concoction(shouldn't be lvling acid spray right away). Which shows how strong the spell is when the support is considered decent with just that. It just does a ton of damage and stuns for a long time.
Definitely a good support but pretty boring to me, and kinda sucks to babysit if your carry can't go on people. Great for roaming to mid and fucking someone in the ass though.
My favorite support is still Rubick, since he does everything, stays relevant the entire game, can single handedly win the game, strong early game support, strong early game ganks, can babysit. Just great all around, only downside is you need a solid knowledge of the game to know what and when to steal shit. Nothing beats stealing a black hole and getting a 4man hole on a losing fight and turning it into a teamwipe though.