Dunno what to tell you, I have literally done this dozens of times this year alone, and plenty of years prior. I have seen the screen readouts, and again, the turnstile readout is seat and name. They can pull your group on the PC screen or a handheld scanner if they want, but most don't or won't. If you were trying to board first they might. Hence why I said second main boarding group, every time.

man up and pay for a premium ticket

With the way you are talking you seem to not understand how premium boarding works. Nothing about boarding groups is remotely about boarding efficiently. Literally not one bit of it. 0%. It is 100% point loyalty and status. They do not board back to front, nor do they board in staggered patterns to spread traffic, they board from front to back, starting with the higher status and going down. Zones are assigned again based on status of the flyer and seat position. You can be in Zone 1 while in sest 35F if you are right status and sometimes still get pushed to Zone 4 or 5 when sitting in Premium/comfort+.

What I'm doing actually is less traffic overall. I specifically choose a seat in the rear of the plane for this reason. Zone two boards in front midsection. Again, boarding groups are not efficient, go watch a whole CGP Grey video on that if you don't believe me, he talks about it for 20 minutes. But I'm getting situated, stowing my things, clearing aisle obstacles, and ready by the time anyone else gets to the rear, and all I have to do is let them in, which is considerably faster than the traffic jam that zone boarding causes from all passengers being in the same area at once. Everything I do happens simultaneously while the rest of the front midsection is a natural traffic disaster because everyone in one section is boarding at once. It is as inefficient as possible, and I'm playing no part in extending it. I don't even stand in their section I blast straight through it to the back, where there is no one.

Efficient boarding, without a literal line order, would be something like waves going from back to front staggered every third or 4th row. Zone 1A, 1B, 1C, etc. No airline does this. Because they want to sell you faster boarding. I've been on the highest status tiers at various times on 3 of the airlines, and again, nothing is different they just seat you first because your loyalty points regardless of position in the plane.

I've flown millions of miles at this point across the 5 major airlines in the US (sadly still a few hundred thousand short on Delta because it's not consolidated), and spent more than I care to think about for work travel. They will kick you back down to Zone 7 without a second thought, and none of it has to do with efficiency. And none of what I've said above slows anyone down. You're buying into marketing schlock.