...or use the usermod command to modify the UID and GID of each user in its respective distro. This is what I've done, and it works well so far.
I haven't checked what user "tc" is yet, but in my current setup I have two distros in which the regular user.group is 1001.50 to be compatible with Damn Small (it was easier to set my Debian user persistently to use the same IDs as the non-persistent DSL). If those IDs are different in TC I'll probably add a TC bootlocal command to change that, since all of my persistent files are already owned by 1001.50