Pouches that I've used w/ my VZ58:
Spiritus Spud Pouch: https://www.spiritussystems.com/spud-pouch/
Fits 1x mag great. Not ideal, so wouldn't use it as a speed reload but def. holds it secure. I'd imagine the JSTA pouch would also hold one well if you use a 308 kydex insert. LMK if you're interested and I'll do a test fit when my JSTA arrives this week.
Direct Action Gear Rifle Speed Reload: https://us.directactiongear.com/rifle-speed-reload-pouch-short#AGR
I run this on my belt for speed reloads. The have both a short and tall version and both seem to work very well. Easy to draw out and reindex. Even the short one holds the mags very securely without the need for additional bungie loops, but the pouch is designed so those can be easily added if needed.
Whiskey Two Four Acc. Panel 05: https://www.wtfidea.com/accessory-panel-05-insert-compatible/
This, along with their 308 elastic inserts & esstac 308 kydex mag clips, is what I run as a chest rig. It is slightly wider and "deeper" than some other chest rigs so you can easily fit 3x mags side by side across with some room to spare. Holds securely and easily to draw and reindex. I'm sure a similar set up w/ Haley etc... would work well, but those are a bit smaller so IDK if you'd get 3x mags across, might only fit two