When the boys were younger, umpires often told us at ground rules that the zone would be "from chalk line to chalk line" and for the boys to "get up there and swing." None of us had a problem with it, as it forced the kids to get the bats off their shoulders. Not uncommon, I'm sure.
As for curve balls/offspeed, so far this HS season I'd say they have been called well, and that's not my opinion, that's based on what the catchers have to say. We have a couple of pitchers with pretty good command that will "test the zone" in the appropriate counts, particularly the high strike. If they start getting a few calls upstairs early in the game, they'll attack it.
Speaking of pitches off the plate, last summer 2024 was in the top of the 7th with a 1-0 lead against a solid team where he was pretty much hitting his spots and getting weak contact and a handful of Ks. Got the first two outs, then hit a kid up-and-in (leaned into it -- smart batter), got p.o.'d and walked the next batter. So now he as runners on 1st and 2nd with a beast at the plate that he struck out the first time then hit up-and-in the second time (he also leaned in). I think he got 1-2 on him, went down off the plate, and watched the ball get pulled and sail over the wall -- by a lot. 2024 couldn't believe what had just happened, kneeled, and put his head in his hand while the other side went bananas and the beast sloooow trotted the bases. What he (and the catcher) didn't notice was that the beast moved in the box and was practically standing on the plate, effectively putting the "outside fastball" right in his wheelhouse!