One thought is use the stock WTB TCS i23 28 spoke wheels for road use with road tires and a road oriented cassette, then add a 2nd beefier set of wheels with the Riddler tires and the existing 11-34 cassette. You retain the hill gears for gravel use. The question is - how heavy are you, and do you need a 32 spoke wheel ?, or can you get away with a lighter wheel, especially in the rear. You can easily get a set of Shimano GRX 24 spoke gravel wheels, plus cassette, plus rotors, plus whatever tire size you want, for about $600. I’m having a spare rear wheel built from Universal Cycles, Mavic rim, 105 hub, 32 DT double butted spokes, hand built. The price for front and rear is $460. Note though that currently, Shimano CenterLock disc rotors are really hard to find.
I would do wheels first and not yet change the crank. A 46/30 is a really useful range for hills. Also ask yourself how fast you need to go, as a 46 ring with an 11 cog is about 26-28 mph. Do you need more speed than that ?, or do you just need a cassette with closer gearing ?. I run a 12-25 on my road wheels for mostly flat riding with a few local hills (Long Island), where I want the one tooth jumps thru a lot of the range.
Try that a while, before swapping cranks. It’s about $135 or so to go to a 105 crank with 50/34 rings and a new b-bracket. I’ve the same bike as BTW, love it.