There might have been some British carriers in Berlin, but the only photos that I remember were of the Borgward IV. They had 6 PSK that could be ripple fired. I believe the tactic was to dart out of cover, ripple fire, dodge back and reload.
https://en.wikipedia.org/wiki/Borgward_IV In ASL terms a SPA but with a 6 shot PSK rather than a gun.
From what I have read the Universal Carriers captured in France were the mainly if not exclusively Mk I, along with the slightly different Bren and Scout Carriers. Mk IIs could have been captured in NA as well as Italy and of course some captured from the Soviets. All those Universal Mk I & II, Scout and Bren are well covered by ASL's differently armed carriers. The Universal Carrier conversion had 3 PSK strapped over the engine deck, wooden crates of PSK rounds at the rear, a LMG and 6 PF as standard.
I'm not clear what the tactics. Given that a carrier held only 4 (or 6 at a very, very tight squeeze) that would mean a driver and the other 3 armed with a PSK each. I suppose the PSK could be fired while strapped down on the engine deck, but except for an emergency I would regard that as a hairy experience and not one I would recommend.
So in ASL terms it's just a carrier that comes with (3?) PSK rather than a PIAT. If fired from a vehicle then it would suffer Backblast like if fired from a building. In reality a good, experienced crew would probably manage it safely, but ... and we don't want to encourage that sort of thing, anyway.