New Zealand First get punished every time they go into coalition because they explicitly pitch themselves as a radical alternative that cuts through the chaff of both of the parties they end up going into coalition with. TOP will probably face something similar.
Random election thoughts: Opp are gonna suffer the thing NZF suffered where because they are explicitly on the fence they will piss off around 20% of their voters no matter who they choose to put in power and get thrown out in the next elections. That's the ride theyve bought.