loop in connectors inside steel conduit, what is best to use?

I did some work during a large open plan office refurb and the foreign electricians used LSOF flex for all of the fixed electrics. M&E consultant and main contractor went ballistic and threatened non acceptance etc but customer (American owned legal firm) stepped in and overrode them.

How about using these?, https://uk.rs-online.com/web/p/crimp-bootlace-ferrules/1849682/

I have two places where a branch exists. Two 2.5mil stranded cables in the steel conduit, that I would use a single bootlace ferule on. And the cable that is the branch which solid core T&E. I would then put the two conductors in the one screw terminal on the socket.

Previously is was shoved in there. I can put it all back, but I not comfortable that it is all secure.

I could try and use wago connectors but the back box is 25mm I am would prefer not replace it, and I am not sure on space etc.

Ferrules are alright if they are the right size and the proper crimper is used.

I see the ones in the link will accept 2 x 2.5mm² conductors so ...