Why not? A 300 year half life is still potent.
Lots of advantages cited, but it's hard enough to restart the LWR industry, let alone license a plant based on new technology.
With only a 300 year storage requirement maybe all the billions spent on Yucca Mt. can actually go to good use. Especially since the level of waste is 1% of a similar LWR.
No need to scrap current LWRs but given the alleged intrinsically safe nature the approval process should not be anywhere near the level of a LWR. Maybe 2X of a coal plant.
There are current designs. There are a few current operating reactor so a complete blank sheet of paper is not needed but certainly engineering an upscaling would be required.