There can be an issue caused by the spigot of the cylinder contacting the magneto housing preventing the gasket faces meeting, so watch out for that. It's certainly something that if unaddressed can deflect the spigot inwards causing a reduction of piston to bore clearance
Rectification involves removal of material either from the spigot or from the housing. If proper port matching of the lower transfers is done, that in itself will effect a cure.