Headroom never hurts, but powering up to the quoted specs should be okay. Just watch out for heat. The Memory Palace has an aux 12V DC connector to power the digital platform’s core circuitry. This reduces the power draw from 650mA on the +12V Euro rail down to just 40mA on +12V Euro rail if you power it from an external wall wart adapter. You don’t have to worry about it being a switching supply in this case, because it’s powering the digital rail only (analog rails are derived from the clean euro supply’s +/-12V.) If you have the Vessel case, there’s already an internal DC jack you can use for chaining. We have a small access panel planned for this, too (that gives the Vessel case power/sync chaining features to the front of a rack in a different case.)
The Erogenous Tones Structure module will have the same technique for sourcing digital power externally from the EuroRack rails as an option. Rick and I have worked on the circuit together.
Even at 650mA, which is over the typical LZX budget, if you balance it out with some of the LZX modules which are under the power budget per HP (Escher Sketch is one!), you should still be okay. I’m currently running a full Vessel with Memory Palace and Escher Sketch, and the top row full of Expedition modules, and having no issues running it all off the Malekko Power.