I decided to clean my PC after a year and took the opportunity to try the Arctic MX-7 also considering the good rating on Igor's Lab.
The Helios hasn't moved an inch, as it should.
MX-7 was applied by spreading it with a glove over the entire surface, I added a little more in the center just to "be sure".
9800X3D, B850M Mortar, Thermalright Phantom Spirit 120 SE, no CO offset and stock PBO values.
Considering that the Heilos was a year old and that the PC was also dusty, I'm not very satisfied with the MX-7, its consistency is very strange in any case sooner or later it will age and it will do so faster than the Heilos showing signs of pump-out.
I'm definitely limited by the heatsink, too. Perhaps a more powerful liquid cooler could squeeze out a few more degrees.
In any case, it's not worth it for me, given all the benefits of the phase-variable pad.
I hope this can be useful to someone.