In general, I'd say no to the chest mounted holster. But, if you have a special purpose for it, then go for it.
I use a Safariland 7TS light bearing holster on my PC mounted up high on the chest (though pointing down, mounted near where a mag shingle would go would be better if you have the space). I use it for home defense; if I wake up in the middle of the night to a break-in, all I have to do is throw on my plate carrier and holster the pistol. This way I have good retention on the gun with quick draw via the ALS mechanism, extra pistol mags, ifak, and whatever else I want, all by throwing on the carrier. You can be very well equipped in a matter of seconds without having to think about it. For that purpose, it makes a ton of sense. But I'd definitely rip the holster off (QLS system attached to a molle fork adapter) if I was doing anything outside the home, ESPECIALLY since TX doesn't recognize the right to carry pistols openly via any method other than shoulder or belt holster (weird... dumb...)