Since the recent nerf to domis they no longer serve any purpose within their own mechanics. Domis have all the disadvantages of an antiheavy, but since they can no longer capture heavies they have none of the advantages.
-They have a super long cooldown after every capture, like an antiheavy.
-All captured units are freed if the domi dies, which only makes sense if the units are more expensive than the domi itself.
-They're too slow to even keep up with an aspis.
-They die when sneezed at.
Even the domi mission is no longer winnable under the current balance. At least not with anything I've tried thus far, including adding rackets or gnats as supports. Really my last ditch effort with that is just to forget domis entirely and spam scorchers and scalpels instead. If none of the disadvantages are removed then they just aren't viable.