PrimaLuna preamps. Use of 5R4GY tubes instead of 5AR4 / GZ34. Yes or no?

Post addressed to the owners of Primaluna preamplifiers. Have you tried to replace the 5AR4 / GZ34 rectifier valves with 5R4GY? Although the valves have completely different values, they are recommended as an upgrade on the Primaluna website and by UPSCALE Audio.
https://www.primaluna-usa.com/tube-rolling
I would like to try these valves on my Prologue 3 but I am afraid of some breakage.
I would like to know your experiences.
Thank you.
Alessandro