I know I'm asking because somebody in the next 7 days is gonna ask me why he can't and I'm gonna need to have the answer.
I think that person would have a hard time arguing any more than a single piece can placed and that deployment skills can be used more than once per deployment. Same with Metachemistry right?
I couldn't find one. Other than it says Minelayer "The user of this Special Skill can secure his point of deployment by placing A Mine, or other Deployable Weapon or piece of Equipment he carries, nearby to prevent enemy Troopers from approaching."
Metachem has a very specific timing listed "Immediately after placing the Trooper with MetaChemistry on the table for deployment, you may roll once on the MetaChemistry Table to determine that Trooper’s extra MOD or Special Skill." That would prevent the argument of I wanna use it again, minelayer doesn't have that timing thing.
Please remember I'm approaching this from needing to be able to satisfactorily explain it to someone.