Here's a mod for the Asetek Invicta brake pedal to replace the elastomer with a spring.

Here's the list of springs used:

Yellow = 60kg https://fr.aliexpress.com/item/1005005480939399.html
Blue = 100kg https://fr.aliexpress.com/item/1005005481736624.html
Red = 146kg https://fr.aliexpress.com/item/1005005493840417.html
Green = 219kg https://fr.aliexpress.com/item/1005005494290889.html

Outside diameter 27mm
inner diameter 13.5mm+
length 30mm

My preference is for red. The feel of the regressive braking is much better.
I printed centering blocks in PLA with 100% filling and walls of 6.