30/46 and 11-36 is a range of 46/30*36/11 = 502%, with a chain capacity of 41T.
I don't think you'll find a 31T chainring, so change that to 30T.
30/48 and 11-40 is a range of 48/30*40/11 = 581%, with a chain capacity of 47T.
Lets assume that you have a real diameter of 26 inches.
Your top gear is either 108.7 GI, or 113.5 GI.
Your low gear is either 21.7 GI, or 19.5 GI
Instead of going up to a 40T cog, why not drop the inner chainring size to get a similar range, and with the benefit of a smaller chain capacity? You'll also get closer gear spacing this way.
26/46 and 11-34 gives you a range of 547%, with a chain capacity of 43T, and 108.7 GI to 19.9 GI.
However with a 20T jump in the chainrings, you won't be able to use the outer 3 cogs when on the inner chainring due to the chain rubbing on the outer chainring, but this is fine since those gears are overlapped anyway, and are available on the big-big combination. You can also add 0.1-0.3mm shims to the inner chainring to increase the gap to the outer chainring to make the chain clear an additional cog. 20T jump also requires a chain catcher and some front derailleur adjustments.
I am a slow rider that's not good with climbs, so I have 14 to 72.6 GI, with a 519% range.
On flatter surfaces, I would prefer 17 to 82 GI. I am rarely ever going faster than 82 GI. However, your requirements will differ than mine.
You should plug in the data into a table to see which gear combinations work for you, and whether the gear spacing from inner chainring 7th to outer chainring 2nd or 3rd is sufficient in a 20T jump.
You should look also the Shimano specs website to see the total chain capacity and max cog size to determine if the rear derailleur will be able to take the teeth combinations that you want.
https://productinfo.shimano.com/#/sp...r%20Derailleur
https://productinfo.shimano.com/#/sp...r%20Derailleur
https://productinfo.shimano.com/#/sp...r%20Derailleur
The gravel RD-RX400 rear derailleur can only go up to 36T cog with a 41T chain capacity. You'll have trouble if you want to change to a setup with a larger capacity.
Instead, the trekking RD-T6000-SGS can go up to 36T cog with a 47T chain capacity. The extra 5T in chain capacity will give you more options.
Some of the mountain RD for 10 speed go up to 36T cog with 43T chain capacity.
If you want to go up to 40T cog, you might be able to use the derailleurs that are rated to 36T, but you'll have to research the internet to see if other people have been successful. If not, then you could try the Wolf roadlink to increase the gap between the pulley and the cogs. Otherwise you could try the mountain RD-M8000-SGS up to 46T cog with 47T chain capacity, for a very wide range of options. However, it's made for 11-speed. But some people report that they could use some specific 10 speed mountain shifters on the 11-speed mountain derailleurs. Although, other sources claim that the pull ratios are different. So you'll have to do some research and experimentation.
https://forums.mtbr.com/drivetrain-s...in-947611.html
https://forums.mtbr.com/drivetrain-s...y-1017063.html