Hmmm… This is quite concerning, as I do frequently use Alt codes for non-standard characters. I hope there’s a way this could be fixed so that Alt+numpad works as you’d normally expect it to…
If not, there is a possible alternate option… I have a smaller laptop used for work provided by my employer. As the built-in keyboard doesn’t have a numpad, I use a USB connected one.
Despite the numpad being a separate device, I can still use Alt codes on it by holding Fn+Alt+numpad. Can you see if that’ll work on the Framework keyboard+numpad?