I'd advise against an early transition (e.g. first 5 minutes) as the cost of a new factory is noticeable at your level (if you were playing at 2000 ELO it'd be viable, but you're in the big boy club now).
Against Hover both Rover and Tank are good. Kodachis and Scorchers can kite and beat Bolas *only when moving away from the Bolas*, so careful micro is needed. This works particularly well with a Fencer or two to force engagements or push back the Bolas (Fencers are almost cost effective against Bolas by themselves). When the Bolas numbers get high a Ripper or two will fend them off (Ripper AoE is absolutely devastating and Rippers are fairly fast).
One thing to note is that Bolas often do worse when fighting many units and NOT running away from them as their attacks will be targetting the lowest HP unit (which is probably the one maximally slowed), meaning most of the others will be unslowed. However, when Bolas are moving away from the enemy army the slowed enemy units will drop out of range quickly, removing them from the fight and making the Bolas target the unslowed ones, reducing their DPS.
So Bolas are much stronger and harder to kill when they are moving away from you.
And another thing, if facing Bolas as hover mirror it's important to note that Daggers are
fast and have very high front loaded damage even if they can't take an equal mass of Bolas. So the best defence in that case can be offence, using your daggers to kill any expansions or isolated Bolas by going around and avoiding the Bolas swarm. You'll need to ensure you'll be able to react if the Bolas swarm goes straight for your fac, but the very high Dagger speed often ensures you can get there in time and your Commander+Lotuses should be enough of a home turf advantage to kill the Bolas swarm when the Daggers arrive.
If the Bolas swarm goes for your expansions? Meh, your Dagger swarm is much faster and can kill more mexes per unit time, you can also split your horde without worry (hitting multiple targets at once) because you're fast enough to recombine if needed.
If the Bolas swarm splits up to kill multiple expansions? Get your Dagger swarm to kill each isolated Bolas swarm! Though normally the mere threat of this will force your opponent to keep any splits within a short distance of eachother.
