I use the A Zooms also for malfunction clearing, I don't see the need to use them for striker fired pistol dry fire practice. Pistol's with hammer's are a little different, most say it doesn't harm them at all but some feel safer using a snap cap.
We buy cheap plastic ones by the bag, and dry fire the heck out of our pistols. When they get chewed up we just throw them away and get more, though you may be surprised how long the cheap ones last.
I seem to remember my CZ-75 coming with a pair of plastic caps that had replaceable rubber "primers". They lasted me a very long time.
A-Zoom caps are nice, and I do have a few pairs, but IMO they get chewed up prety fast also - especially the shotgun shells.
The only reason to use Snap-Caps in a modern defensive pistol is to practice malfunction clearance. There is absolutely no need for them to practice drawing and re-holstering.
Once again, I'm in agreement with chez. No reason for them for your stated intent.
I have an xds, and if you practice consistently you'll get smooth draws. Smooth is fast.
Be advised of a potential issue with A Zooms. If you are loading one in the magazine and cycling the round into the chamber, the aluminum of the A Zoom will wear and burr where the "brass" portion meets the "bullet" portion. Eventually, the round will be pushed further and further into the chamber and stick. You can remove the burr, but eventually the snap cap will wear out from repeated loadings. Similar to when live rounds will experience set back of the bullet from repeated chamberings. For actual dry firing action, they do last forever.
A Zooms in revolvers-the rim will harden and break off completely, eventually.