Starting off with a wonderful tone.
Meter on all throws doesn't scale, period. The parts of throws that are hits (Buer, end of Double's airthrow, end of Excellabella) scale, but things while the opponent is thrown do not.
I
sort of agree vs corpses, but nothing suffers a meter gain penalty when used as an assist...
And no, true unblockables (or even single-frame humanly-unblockable things like Eddie's) don't exist with command throws. Hard-to-escape setups yes, but that's not the same thing - there's no situation where you REQUIRE an invincible reversal or superhuman speed to escape. You just don't get to escape by doing the same thing in all cases.
I'm not gonna explain it in-depth again, but basically: If any throw whiffs through your jump startup, you are granted protection to block any while-rising attack after jumping. The protection lasts longer than everyone's fastest air attack. So either you are protected, or you can poke the person doing the command grab, or you can poke the air-throwing character.
If you were airborne
before the throw went active, as opposed to in jump startup, you do not get the protection. So simply holding up-back with no timing will likely get you snagged, yes. But it does not require a jump-cancelled special move.
I might consider making this protection more lenient, but I thoroughly tested and it works in all cases that are currently in the game where poking out is not possible.
And every character does have a way to escape that is not jump-cancelled ground specials or jumping, even if there were no protection. Some require meter, but most do not. Robo has M Danger, Eliza has air super, etc.
Regardless of whether I agreed about there being a problem or not, nothing's getting changed for release at this point, so either way my suggestion is to learn how to either deal with it or mitigate the effects.
If you get grabbed by the assist, the setup is not repeatable tightly because they can't call the assist again until you recover from hitstun. As well, the followup combo is scaled extra. Plus, they are sacrificing H LnL or L Beat Extend or H Brass or whatever for the setup.
If they are doing it to you when you're falling (for example, Fukua c.MP->c.HK whiff, command throw), every character has a way to change their air momentum and delay their landing so that there is no consistent way to set up a meaty command grab vs their landing, which means there is no consistent way to set up this setup either.