Mil-Spec Monkey has a highly-adjustable Wrap Holster for worth checking out.
It’s made for EDC-style bags with loop/pile interior zones. This pouch was originally sized to fit combat pistols, but it also fits rifle magazines and "flat" electronics such as smartphones.
“After using many velcro backed holsters that always seemed to snag on the front sight during a draw, we came up with this one to offer clean draws even on full-sized pistols with suppressor sights and or tac-lights,” MSM officials say.
Since the whole pouch is made of VELCRO Brand ONE-WRAP, you can get creative with the shape such as making a slight cone shape resulting in a reasonable opening, but a tight fit when the item is pushed in all the way, according to MSM officials.
MSM makes it very clear on its site that the holster requires extra care to use it safely.
“WARNING: Due to the highly customizable nature of this design care must be given to the setup when using with a pistol to make sure no extra overlapping material will get in the way of the trigger during draw or reholstering. USE AT YOUR OWN RISK! Like many holsters, long term use may scuff items inserted into this pouch.”
If any further small tweaks are desired, the one-wrap material is easy to modify by cutting. A jump strap is included for when extra retention is needed, yet is very easy to remove when not needed.
This works especially well on this setup where one can release the jump strap by moving the pull tab or using their finger to break to connection, MSM officials say.
The Wrap Holster is made by Tactical Tailor and retails for $12.