ACM is made of 2 aluminum layers with an internal filler 2 or more mm thick. The filler is often PE. Since the outer layers are aluminum, I suspect no issues with higher temperatures. The limiting factor will be the filler. I suggest that you heat a piece in an oven and examine the behaviour.
The only part of the printer that heats up is the hotend with the nozzle. The heatbreak isolates the hot part from the rest of the printer.
I have a plastic mount (3dktop) that can handle temperatures well above 150°C, but even before with an ABS made mount, I printed PC @ 320°C without problems.
I think that the only limiting factor for the ACM will be the temperature of the environment = heated chamber.