Can i mount Steelie magnet onto my iphone 12 case and not cause harm to the phone?

I’ve used Steelie magnets on my iphone cases for my last 2 phones; I started using it for the car mount but quickly made more use of sticking it to anything metal (i.e. my forklift at work) .. I just upgraded to the 12 Pro from the XS and when i went to place the magnet to get an idea of where to remove the adhesive and permanently stick it, it lightly stuck on its own. I’ve never worried about Steelie before because the magnet worked outwardly but now that the phone itself is attracting the magnet, i’m not sure if its safe to use. I dont care for wireless charging so thats not a concern to me, i just dont want to damage the phone. Does anyone know if its still ok to mount the magnet to my otterbox defender case and not cause damage to the iphone?

*attached photo of my previous iphone case with steelie for reference alongside the new, unused steelie*