RE: 6.4.0 Firmware for Prusa CORE One + & CORE One
After some more experimentation, it seems that setting the chamber fans to 0% disables the chamber temperature control which should allow it to be manipulated above 55c manually.
I still feel that the 55c limit is too low and needs revising up to (say) 65c to cater for the high temp hotend and use of higher end filaments in the Core One. Hopefully the devs will reconsider.
The chamber is heated passively by the heat bed. Even with the heat bed at 120° (which is as high as it can go) and an insulated chamber the max I was able to reach was 60°. Beyond that, the chamber will need an active heater. And, as I pointed out in a previous post, the acrylic panels (door, side panels) will start to warp and the love board electronics might start having issues if one goes above this.
It really isn't "up to the devs" in that there is nothing firmware-wise that will make it go hotter. Essentially the entire printer enclosure would need to be redesigned. Hopefully Prusa will introduce a Core One HT.