I trained my peach trees to have better angles, but cherries do better upright. I trained mine using the KGB system. Which is not concerned with angles, more about the number of fruting branches.
Yes, you need to keep them trained for about a year I would say. I took mine off my peach trees early, and they went straight upwards again! Look rather funny now!

My peaches are actually doing well without lowering branches. The cherry trees have very narrow angles and I know they would break with snow. I've seen that with some ornamental trees on the trees.

Right now I lower them about 5 degree more than the angle I want to train. They are sizable branches and are about 1/2" diameter. I know they will come right back if I release them so early. They are the main scaffolds and dividers would not work. I may just keep the weight for longer time.

Funny as my cherries are fine, it's the peaches that need help.

60 and 65 degrees are the same thing in net result. But yes go a little more then you want. I have tied young branches and had them take in weeks. I think it was Olpea who said tying in winter has an effect, presumable due to the freeze-thaw cycles. No downside to it, you don't have to mow around your weights.

The weights have to be on the ground holding firm.

On my biggest apple tree I had a large branch that wouldn't train so I found a low branch going the right direction and cut off the rest. The little branch really took off and I'm glad I did it.

Branch bending isn't called for with Backyard Orchard Culture. Trees are shaped by pruning.

I do not want to cut 1/2" diameter branches off some young trees. It is well known that, some trees, like cherry, are notorious for its upright growth. Pruning won't do it.

Many other trees are also trained lower by tying, branch dividers, and with other means. Even some of the apple trees are trained that way.

My other question is that, if I over correct the branches a little. Then the tree would grow at the over-corrected position. When I release the weight, the new growth would be still out of position. Well, I figure I can only worry about the main scaffold. Train the secondary later, or just prune selectively.

Not true mr clint they do it all the time. It's in many of the videos especially on espalier. All we are doing shaping the tree the way we want.