So you're saying that your MecGar mags nosedive, and cause rounds to stand up vertically in all your guns? That's so strange, I've never had a problem with mine. Were your mags purchased new or used / old?
For cross-compatibility, you have to be careful. While the MecGar mag may fit and "click" in, the differences in the follower and height of the magazine/feed lips and position of the mag catch may differ than the factory Taurus mag.
You could take the slide off the gun and just eyeball it: how high do the feed lips go with the factory mag in place? How high do the MecGar feed lips go? Try it with a round in the mag if you can't tell with an empty mag. But don't forget to safety check when you reassemble.
If you have dial calipers, or digital calipers, measure from the top of the mag catch hole to the top of the feed lips at the front using the large jaws. Do this for both the factory and Mec Gar mag to compare. Your picture of a round completely standing up is so bizarre to me, IMO there has to be a LOT of empty space in that area for this to happen. This makes me think your mec gar mag sits too low, which may mean the mag catch cutout is higher up on the mag than is optimal. But it's not like you can tailor it if that's the case because you can't just ratchet the whole magazine upwards, you are limited by the base plate, length of mag, and existing hole kind of puts a damper on things.
In my pistols, if a round has moved forward enough to come out from underneath the feed lips, it's pretty much been chambered. There's just not enough free space for that to happen. I've never had a round stand up like that.
If you have really old mags, then yes new mag springs may help.
good luck.