If you think legacy holders should pay something, I maybe agree with that in principle. [But definitely not signing a service agreement which forces a legacy holder to become an LIR.] And maybe that’s a discussion that could be had once there was some hard data.

...

If you want legacy holders to pay, both the RIPE and NCC policy making machinery is open to you.

Legacy holders already pay.  See screenshot from my LIR bill for 2020.  Been like that since our 2016 bill.

Regards,
Hank

Caveat: The views expressed above are solely my own and do not express the views or opinions of my employer