my new bike is coming with 1×10. 30 front 42 largest sprocket on back.
on a full rigid bike tho, so i hope it will suffice. if i had bought a susser i would have stuck with 22/32 front and a 12/36 back.

Could always stick a 28t on there if you’re really worried

Is your 2×9 based on a double crank or triple with the big ring taken off? If the latter then 30t nw or 32t nw oval in middle ring position gives pretty good chain line.
2×10 cranks may need faff with spacers.
I think I recall I live near you RRR. I’m the wrong side of 14 stone and ride the peaks on 1×10 with 11-42 x32 oval on a 33lb fs or 11-40x30nw on HT . It’s fine. I’ve not found anything I need to push up yet. Walking is still sometimes quicker though 😀

More teeth on the down part of the stroke. Helps if you can’t pedal in perfect circles.
Free speed!
Cheap as chips from superstar

if you don’t want a new freehub then Sunrace already have an 11-46 shimano fit 11 speed cassette out. Or you can wait for the new XT 11-46.

Failing that you can change your freehub to an XD one and fit a 10-42 Sram cassette or a 9-44T E13 TRS ones. Or you can go with Hopes own cassette and it’s freehub which will give you 10-44.

If you have regular 104 bcd cranks then you are limited to a 30T round ring or 32T oval ring. You can get 64 bcd (granny tabs) oval rings from absolute black that go up to 28T but I would only use them on a 29er as you would be spinning out like crazy.

Cheapest option if you don’t want some new direct mount cranks is 11 speed shifter and RD, sunrace or shimano 11-46 cassette and then either a 30T round or 32T oval chainring.

I have just set up my 26″ hard tail with 11-42 and a 34T oval. Absolutely fine on the ups and never ran out of top end on the downs. On my 650b full susser I will probably go with 32T oval and 11-42 or 34T oval and 11-46.

29er (Solaris) I am sticking with 3×10 as it’s a mile munching bike and a 3×10 WILL last longer due to more optimal chainline, especially in winter when things get gritty.