Stigmata looks great, but for that price consider the Foundry Overland frameset (or full build). Titanium will last forever (unless you break it) but the bigger reason I would consider a frame like the Overland is the BSA bottom bracket. PF30 has a reputation for creaking. Overland fits big (38mm) tires and has a nice middleground geometry. Maybe not quite as slack as Stigmata, but great do-it-all geo.
Going to 36t rear hub would be a big step lower for the gearing. And would mean you could easily do it without going “all-in” on Sram
rear hub and those pricey
cassettes. (You can get 40-42t rings that work with conventional 10-11sp cassettes too.). Any of the Sram wifli systems should provide a med cage RD and support for 36t cog. Going bigger probably means buying rear pieces of a 1x rear setup (but not using multiple rings, so not 1x).