XL Hot End to go >400C
I've been researching options to get me to advanced material capability, and hopefully be able to print PEEK or close to it.
There is options from E3D Revo High‑Temp (HT‑X)
https://e3d-online.com/products/revo-high-temperature-hotside?variant=41437847388219
Even with a 450 °C hotend, PEEK needs:
Chamber: 90–160 °C
Bed: 120–160 °C
Ambient stability: no drafts, no cooling fans
I have the enclosure kit for the XL, but it looks like its a stretch.
RE: XL Hot End to go >400C
Im not sure if it is feasible. Let say you make it fit... then you'll have to fork a firmware and do the necessary changes, change your heatbed, provide cooling for the controllers, build a proper enclosure, attach a chamber heater and reprint everything in pccf. There is still the issue if the electronics on the toolhead can cope with the both the heat of the nozzle and the heated chamber. I dont believe Prusa will bother with this since it will probably be an expensive kit and will mean a lot of testing to the upgrade path. Also XL hasn't had any improvement kit imagine making an overhaul kit.