Type-S Silencing Decreases as Domes Stiffens?

I purchased a 7-year old HHKB Pro 2 Type-S keyboard and a new Realforce R2 PFU Limited Edition TKL.

The HHKB is noticeably more tactile than the Realforce and it is harder to stop halfway. When comparing the sounds, it seems like I hear more of the upstroke sounds of the HHKB than the Realforce.

Multiple people have said that Topre domes stiffen with age, but does that make the Type-S dampers less effective? I do not have multiple Realforce keyboards to compare with. Can someone who has new and old silenced HHKB or Realforce keyboards or dome swapped keyboards chime in?

It’s normal. The domes become louder as they stiffen (well at least from my experience). My Pro 1 with soft landing pads sounds louder than my Pro 2 with the exact same parts.

Lubing might help getting rid of the clack, if you are into that.