[smokiniron]

That said, I don't really understand what it does a lot BETTER than a well-designed pocket holster.

For me, I really don't like the weight of the gun in my pocket. The weight is still there, but for me, it seems to ride better on my belt. It may be a matter of perception. Time will tell. The genesis was that I can't afford to experiment with 3-4 holsters at $40-60 apiece. And, I like to make stuff!

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yours included, will be a pain to use from a sitting position. The main constraint when sitting is that a person's pants fabric makes it difficult to get you hand into the pocket, and that may still be a problem with your design.

An IWB holster is far better in that case.
I'm hoping that the firmer shell of my holster will keep the relative 'tightness' of the pants pocket from constraining a draw. Since I'm a fat guy, sometimes I have to squirm around to get in my pocket. This holster seems to help the problem quite a bit....

I wonder if the suspending strap could also "bow" out and get in the way when sitting.

Yes, it bows. But the upper cinch loop can be left a little looser so the strap can rotate some. It bulges, but not much, and doesn't seem to get in the way. I thought about a pivoting hinge point, but thought it was too complicated.

A video of you using it could show that this concern is not valid. (An afterthought: that strap could be used to PULL the holster out a bit, which could be a plus!!)

I'll try to get to this. I'm not of a mind-set to feel the need for quick access (I know that is unwise heresy) but time will likely change my approach.

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but am generally more at ease and comfortable with IWB holsters. IWB holster have other issues (comfort when sitting) which is less a problem with pocket carry.

I'm with you there. I just don't have the bucks to check too many holsters, only to find I don't like them. The XDS is a good IWB gun, so I may just 'roll my own', since I've seen a few belt clip sources. And, I may just make a belt loop style for the fun of it.

- Smokiniron