What deoxy posted is pretty similar to the concept of PA in dda.
It’s productive to think of PA as a wearable vehicle rather than an article of clothing.
As such it doesn’t make sense to wear additional clothing, instead you would install more armor components.
Ideally, weapons would be installed on the PA instead of the player wielding them as usual.
In order to compensate for these limitations, PA weapons would tend to hit harder and have larger magazines, allowing for extended deployment compared to what is allowed by a single magazine of an infantry weapon.
One way to look at the status quo is that survivors are trying to use infantry weaponry (rifles, shotguns, smgs, assault rifles) with PA, which is naturally suboptimal because PA is intended for use with PA-specific weapons. The upgrade path would be to add those PA-specific weapons, which would make it usable for extended sorties, but it would still be fairly bas for all-day use.