It's very difficult to ponder this scenario in isolation from events in Europe, but even in the best case scenario for RN (no war in Europe), many of the weaknesses in the RN will still apply.
By far imo is the carrier force, not only the RN CVs carry less aircraft than KB, but the aircraft themselves are still the likes of Fulmar, Albacore, maybe Sea Hurricanes and some Seafires at best, Skuas, Swordfish. As i understand their combat radius is much shorter than KBs, so in a fight the KB could just stay 250 miles out and keep sending strikes at the british force, with little to fear in the way of retaliation. Not only that but Fulmar and Hurricanes proved completely outmatched by the Zero in 1942, and the Spitfire got roughly handled by the same too in 1943. I can't see the british putting 100 strike aircraft over KB within 1 hour like the USN did at Midway, to overwhelm it's defences.
So imo, as far as a 1942 stright carrier fight, all things being equal the RN will be eaten alive, and KB will cover itself in glory. There is the issue of the supposed carrier night-fighting superiority of the british, but this assumes a lot of things, first the IJN will be kind enough not to attack during the day, let itself be tracked, then be kind to stay within 150 miles or whatever the Albacore's combat radius is. That's a lot of ifs, and any british night strikes, not to mention significant damage, would be more of a fluke rathern than something to be expected.
Even fast forward to 1944, you will have at best Barracudas, Fireflies, Seafires (i'm ignoring for the moment the US planes, afterall the UK would not seem/feel into a tight spot to ask the US for help yet since it's only fighting Japan in this scenario - in fact they will be thinking humiliating to do so) against the B6N, D4Y and improved Zeros. The range advantage firmly remains with IJN. And how many fleet carriers can the RN muster in 1944? I can't see them having 15 fleet carriers and 900 planes like TF58 had, even if they haven't lost a single one to date, certainy not the planes as RN carriers generally carried less aircraft compared to KB. And god forbid if IJN hasn't lost any either. To be honest, even the OTL weakened Ozawa's force, with it's undertrained aircrews, would still be a real threat against whatever carrier force the british could muster in 1944, nevermind a better trained and more numerous IJN carrier force. I can't see the british coping with 300 planes hurled at them and escape without serious damage, nor them being able to send 200 planes at 300 miles after Ozawa.
My view anyway.