"amend 2022 return to change the $7500 IRA to a non-deductible IRA and incur a tax."

Yes.

"(I had neglected to put code BB in the W-2, otherwise Proseries would have found my mistake.)"

And that's part of the amendment, because that is part of Payroll. Your taxpayer might qualify for the Saver's Credit.

"Next, in 2024, I suggest she take the entire IRA kitty worth $16,500"

Yes, that will avoid pro rata tax being computed with every distribution or conversion.

"plus the whopping $2 in earnings"

There are multiple years of contributions in the highest interest and fastest growing era we've seen in these past few years, and there are only $2 of earnings? Any growth is considered taxable income, as well.

"than to file the pesky Form 8606 starting at age 75 for the rest of her life for a minuscule fractional deduction."

There wouldn't be any deductions. It changes how much is taxable income. It's a consideration for Basis = funds that were already taxed going into the deferred account as a pro rated % of the whole tax deferred account, every time any amount is distributed or converted.