Looks like @Jaroot has answered you, as I am part way through replying I might as well finish
No the Dangerous Things ProxLF is not compatiable with the PM3 Easy, So if you can afford to. go for the RDV4 with Dangerous Things ProxLF antenna.
People have had success with the PM3 Easy, but I don’t think they would write as often as a pentester would, But you may just learn the perfect spot to hold it for a clean write.
I have RDV4 and the factory LF antenna wrote fine when held in the correct spot, but the ProxLF antenna makes it just easier.
You could alway start out the EASY 
route , and upgrade if you find you need to.
With regards to
You should have no concerns, standby… I will fetch you a good reference from Amals post…
HERE you go
Basically, even if you are a vampire 
or “The Highlander” 
you should still have no worries with your Dangerous Things
