I’ve received a (appreciably prompt, but unsatisfactory) reply from Elektron on this bug:
This is actually not a bug, it is the intended behavior. However, there are different opinions on how this should work here at Elektron HQ […]
If you manually go to the next pattern in the chain and select it (chain button, arrow keys, yes) it takes the change parameter into account. When a pattern has an infinite master length the pattern will play indefinitely unless there is some user action and this is by design.
After having pointed out, that this conflicts with what the manual states (Section 11.10.2: “However, if CHNG, for instance, is set to 64, the pattern will behave like a pattern consisting of 64 steps regarding cueing and chaining.”), i was told the following:
Yes it seems like the manual is incorrect and I’ll talk to our technical writer about this […]