The A2 Daniel Defence rail doesnt technically fit on the carbine, the bolts that go on the receiver are not spaced the same as the full length version. Only one bolt can secure it https://www.fire-support.co.uk/product/madbull-dd-l85sa80-rail-adapter-for-ics as the two holes shown in the picture are located a milimetre too narrow or wide, cant remember which...
I have managed to fit it on my carbine, though with one less bolt holding it on as a result. It seems secure as it has held for 3-4 years so far, though your mileage may vary.
From that, id guess the new one would have a similar issue, so id think maybe not entirely? though i dont know what the mounting system for the A3 is