Besides a lack of speech that's entirely my fault, LSL6 seems to work okay.
Edit: turned out I already had two saves for KQ7 (how?). #1 in the Continue screen was preselected. I click Delete, the now blank item remains selected. I click Delete, get kicked to the main menu, click Continue again...
lookupSelector: Attempt to send to non-object or invalid script. Address 0000:0000, method selectGameRoom
oom 23, script 23, localCall ffffffff)!
Edit: Continue now does not work at all anymore.