Visonic Powermax Pro (circa 2005) Connecting to Texecom Odyssey 3E via AT-202 Powermax Interface Module

I am taking the opportunity of replacing my mostly inaccessible and old Bell Box while I have scaffolding around the house, with a view to maybe replacing the control panel if/when it gives up the ghost.

Pretty much replacing like-for-like with Texecom Odyssey 3E connecting via an AT-202 Powermax Interface Module - see wiring diagram below:

I connected everything back up as it was originally, and everything appears to work fine, except the strobe does not trigger if I take the trigger from Strobe -ve.

By connecting both Strobe and Bell to Bell Trigger (via two wires), both bell and strobe appear to work OK.

I have no particular problem with doing this, but my question is will it damage anything?

I caveat the following statement with the fact that I am certainly no expert here, but looking at the Powermax Interface PCB, it looks like the feed to the strobe - connection goes through a couple of transistors, from EXT-, whereas the feed to the bell is direct from INT-

Also I'm not entirely sure whether the strobe ever worked with the original box up there, or subsequently stopped working.

Any thoughts on this would be appreciated.