I updated the SDX installs in Altirra last night before trying it in the next day or two on real hardware. First I updated the (virtual) U1MB installation (which mirrors my real hardware with FJC's latest BIOS, SIDEloader and PBI driver). I had no trouble updating and afterward things appear fine. Next I did the (virtual) SIDE2 cart. Again things appear to be fine. However, there is something odd going on.
With just the U1MB installed and booting to SDX, switching to CAR: and then typing a simple DIR | LESS works just fine as expected; I get one page worth of directory contents and a prompt to continue the listing or quit. However, turning the U1MB SDX off and trying the same with the SIDE2 version of SDX gives me odd-ball errors. See screenshot below.
SDX 4.48 running from U1MB:
SDX 4.48 running from SIDE2: