I see. I use xelastec for many IEM but not Monarch. Xelastec simply kills the bass response and sound field of Monarch, the bass dynamic driver’s response doesn’t quite match with Xelastec type, on top of anything it’s quite unconfortable to use already big nozzle with “stick the nozzle with the ear tips around it” type.
I can start a long session discussing how inner ear canal resonance is calculated base on the length of the ear canal, and thus using Xelastec type when inserting the Monarch nozzle deeply inside would change the designed sound signature, but haha I’ll save it for some other day
The original stock tip is CP100 type, and it gives quite comfortable fit for Monarch except its hard material, if you like the sound of stock CP100 mock, the genuine CP100 should serves better
Also Xelastec is pretty useful for many other IEM, so it’s not gonna be a waste, you can use it for others some other day.