Wobble bolts are fine as long as the centre bore of the wheel matches or can be matched to the hub, either with spiggot rings or machine the wheels/hub to suit the bore.
Wheels must sit on the spiggot of the hub as thats what takes the weight, the nuts just secure it in place. If you hold the wheel on with only the nuts then its not going to sit concentric to the hub, cause adverse strain on the nuts holding it on and cause the car to drive funny.
The wobble bolt has been used for years, the one thing to remember is if you are getting any work done to the car tell not to tighten them up with a gun as thats when damage gets done.