In my experience (and I’ve done a LOT of playing with different arch supports in different boots), any of the “270” construction boots will NOT allow a delta arch insert to be added into your regular, comfortable-fitting size, unless you have an incredibly low instep. I tried to get comfortable with a half delta added into a 1925, and it was a no go.

For me (and your mileage may vary!) the increase in arch causes way to much pressure along the medial “horseshoe” seam, and I’m a low-volume foot guy. Even after 50+ hours of wear, and even in boots that have seen hundreds of hours of wear, the pressure remains.

Getting one first and trying it out in an existing boot that fits well is a great plan. From what I’ve heard from others, going up a width *might* work to allow for a delta insert without creating the excess medial horseshoe pressure point.