I’ve done exactly this with my Robin Mather singlespeed frame and love it to bits.
Originally I tested a 26″ on one carbon fork and a 2.1 29er Schwalbe Albert tyre on the open pro front wheel from my road rat. The tyre was very round due to the narrow rim and I got a bit of toe overlap but I liked it.
So I bought a a pair of the same forks a new wheel made up from a 456 hub and DT 29er rim run ghetto tubeless and Mud-x’s front and rear make it my perfect winter bike. It’s not as easy on the wrists at high speed in lumpy terrain as it was with 100mm sus forks but the slightly slacker steering and increased rolling radius make up for that to some degree. There are so many slow speed dips and steps that would have stalled the 26″ wheel which now it just rolls over I’m constantly amazed.
I don’t have toe overlap as it is setup now but I’ll probably fit some lower bars or flip the stem as the slightly higher front end has removed a little of the lightening fast turn it it had.
I should say it had a high BB and steep head angle from the outset and was built specifically for my 5’6″ height around a 100mm fork.
I also have a Dialled Bikes Prince Albert and think that could work well. Maybe a Ragley Piglet would too.