I don't prune tomato plants. Never have, even the *one* terrific year I had in Berkeley where I was hard put to keep up with my caged, staked, *and* tied Romas, canning them in the kitchen. I haven't had success like that since. (Well, I haven't done but two or three years of gardening since, because of the car accident....)
Anyhow. I have six 5-gallon buckets happily growing those vining tomato plants right now. SunGolds, every one of them (according to DH), although I know very well that I brought home Stupice and Roma starts, too...
Lately, because I've been at home around the clock with a little time off on weekends for good behavior (post-op dog whose recovery is very rocky), I've had wide-open access to those happy tomato plants and their suckers, vines, trusses, and cousins.

There won't be many tomatoes for canning this year. Both Vergil (dog) and I really like SunGolds. I offered them to Vesta, so as not to play favorites, but she just turned up her nose at them. The cats just give me The Look.
I wouldn't dream of removing any part of these plants unless it became diseased or in some other way actively destructive to the rest of the plant.
Tomatoes evolved in MesoAmerica as vines sprawling along the ground. Gardeners and commercial growers have devised many means of forcing tomatoes to appear/behave as if they're upright-growing plants, but unless "pruning" other vining plants (e.g., zucchini, sweet potato, morning glory) becomes part of the normal gardening protocol, I'll feel like I'm doing right by my tomato plants, letting them grow
almost as they will, but perhaps more vertically than they would choose.
Cynthia H.
Sunset Zone 17, USDA Zone 9
*Another* refill (the third, maybe?) of pain meds today, when only
one was originally anticipated; three doses a day, when Vergil was "supposed" to have been tapered off. His pain levels don't appear related to the surgery, but I'll be ??? if I know what they
are related to. Poor guy. We're still on the "When doggie sleeps, Mommy can sleep" schedule. *sigh*