"My modular has two A155 modules ... I have not tried chaining the two
of them together to make longer sequences. If fact I'm not sure how
you would do it, any suggestions "

I don't have two A155's to try this with, but since the A150 switch is
bi-directional, it could alternately route the clock signal to first
one, and then the second, A155 in turn, no This would allow the LEDs
to sweep across the two sequencers (although each sequencer would
pause on the 8th step while the other sequencer ran).

You would still need to switch between the two sets of CV signals, but
I think the Trigger signals could just be combined in an A180
Multiples, since they won't overlap.

Joe