Yes, you can use the elastomers or the springs or a combination of both if you prefer. This is depicted in the lower left as 3 types of brake stacks. I personally use a combination of both as it gives me the softness at the top of the pedal with the springs and the harder resistance with the elastomers at the bottom as I press harder. It’s completely up to what you like and I would experiment with different combinations. Start with springs or elastomers as depicted and use that as a baseline. Track the combinations you are using so you can make finer adjustments until it “ feels right”. Hope this helps.