I flew out of LHR a couple of weeks ago and no issues with my forms whatsoever.

Mine are silicone tho.

But if you think about the scanners are designed to pick up metallic objects. So shouldn’t pick up a breast form. I just made sure I took off anything metallics. So that meant all my jewelry came off. I took my shoes off (boots with metal details), watch etc.

Didn’t buzz and not a second glance!