I used to have an absolute oval on my cannondale for racing.i never really felt any difference. Cant remember if it was 32 or 34. But the bike was super light and for racing. This question is for a trail bike for when I go upto the lakes.

Sefton, I genuinely think an AB Oval makes slow cadence climbing significantly easier, because it evens up leg power somewhat between the weakest and strongest parts of the pedal stroke.
And I think a 30 oval feels like a 28 round (so 32 Ov would feel like 30 Rd), but nicer. Smoother.
In the lakes I’d get a 30 and not worry about being able to pedal DH. Plainly changing chainring gives you no increase in range – you can match the 12 speed gear at one end or the other but not both unless you have a very wide range 11 cassette. Don’t bother about range, match the low gear feel.

I’d second trying an oval ring for the riding you describe.

What cassette are you going with then?

I’m baffled by people running 28t chainrings with modern cassettes, spinning out on fast descents feels awful to me, and I love a good sprint on the flat sections so a couldn’t live with anything under 32t. Amazingly Nino Schurter runs 36 and 38t chainrings, that guy is a machine.

I run a 30t front and an 11-51t cassette on my 29er mountain bike

But then I ride up actual mountains. Rarely ever use the 11 much.

10-50 and 32t chainring on my 29er mtb. I’ll be going 28 or 30 front soon as I defo need lower cogs, only time I ever use the highest two cogs is down steep road descents. While I enjoy the downhill road speeds it only constitutes less than 1% of my riding so would rather have the lower gears for the real stuff.

Its an 1×11 42 biggest gear

Its an 1×11 42 biggest gear

I find this manageable on my trail bike with a 30t ring for my local riding (bit hilly) but I much prefer my 10-46t cassette when I go to the Lakes. Makes all the difference getting up climbs like Garburn.

So I’d definitely suggest an oval ring – or even a 28t if poss – if you are keeping that cassette.