Hi St Croix. I make donuts for a living, maybe I can help.
1st, You mention that you've made almost 200 dozen to date, I assume your in a residential kitchen. Teaching yourself and having half that are usable is an accomplishment in itself.
2nd. When I make a mix of dough, (It comes in 50 lb bags from a major distributor in the U.S.) I mix for 15 minutes or until the dough slaps the bowl. It's difficult to explain without standing over a mixer beside you, however when a donut dough is mixed, the sound it makes "changes" It starts to slap the bowl. If you are under mixing your dough that will lead to problems way down the road that are not traceable until you look at your mix times. Someone mentioned gluten in the dough and my experience has been that some is desirable. (I didn't know you could get too much) You achieve gluten in the dough by mix time AND temperature calculations. Check for gluten by pulling off a small piece of the dough between your fingers. Maybe half enough to make a doughnut, and start stretching it out like silly putty. You should be able to stretch it thin enough to see light and shadows through it before it rips. If this doesn't happen, you need to mix longer. You do have a mechanical mixer of some kind right? You can't really do this with a wooden spoon and a bowl.
3rd. Yeast as mentioned in the thread is sensitive to time and temperature. It will only live for so long. I assuming you are using Fleischmann's active yeast or similar? My ratio for dough is 1 ounce of yeast per Quart of water. I use one pound bags of Saf-Instant but it is roughly the same. I'd recommend not activating active yeast. Let the dough and mixing do it for you. I NEVER get the yeast wet before introducing it to the dough. NEBER EBER!
Temperature wise, I calculate for 80 degrees Fahrenheit. This is the formula: 3x80=240 (3 comes from 1-Air temp. 2-Dry Mix temp. and 3 will be the liquid temp-the formula gives you). Take your dry mix temp. an example: 78 degrees. Then your air temp. say 76 degrees and subtract these from 240 you should have 86 now. Then figure in friction during mixing. 15 minutes mixing equals 30 degrees is a safe estimate to start. So I would need 56 degree water to achieve an 80 degree mix.
Anyway the point here is that if you are using "warm" milk and room temperature ingredients plus you activated the yeast using warm water, Your mix is too hot and will kill your yeast that means no rising or at best inconsistent rising. At 80 degrees, My dough sits in the bowl for 40 minutes tops. And not in a warm spot either. I put it away from circulating air with a clean apron covering it at room temperature. Does your dough smell like nasty beer when you go to roll it out? If so, I would suspect the temperature of your mix.
4th. Someone mentioned that when you touch your dough and the indentation remains that its ready to roll out. I prefer to roll it earlier. First off, take a cookie sheet, dust it with flour (not grease) make a loaf of your dough and set it on the pan and cover. You will have a more manageable loaf when it comes time for rolling it. Try to place your donuts on whatever you are going to cook them on. Fryer basket, bottom of a metal colander, We use 23" by 23" screens in a commercial setting but that's not practical for you. You need something that you can dip in the shortening or oil without touching the doughnut until it's time to flip it. But it also needs to be able to support the doughnut. A cookie cooling rack is too widely spaced... Place the cut doughnut somewhere warm AND Humid. Humidity makes the doughnut spread and temperature makes it rise. If you leave a doughnut "out", it will develop a skin and won't rise after that and will just be dense once fried. I was brainstorming and maybe you have one of those potpourri cookers with the little candle in the bottom and the ceramic bowl on top usually a few bucks at a Wal Mart. NO POTPOURRI necessary LOL just put some water in top, and light the candle, place in the bottom of your oven and put your donuts over it. You don't need more than 120 degrees Fahrenheit to proof donuts. I've worked in shops whose proof box consisted of a coil hotplate and a stainless bowl of water on it, and it works fine. While proofing, this is when the indentation thing comes in. Touch a doughnut on its side gently. When the dent hardly pushes back or doesn't at all they are done proofing.
*TIP* don't fry donuts straight out of proofing. They are moist and will make a much bigger mess of your kitchen with oil splatter then if you wait 5 minutes for them to dry a little. Fry at 375 for 35 to 45 seconds per side until nice and golden browned. Another tip. Take a chopstick and flip the doughnut from underneath,You won't make any marks on the cooked side :)
Sorry for the wall of text, however I love making donuts and there is a lot more science to it than most folks know. Eventually I'm going to make some videos on different aspects of doughnut making, maybe you folks would like to see.