The meta answer is NICKELBACK (hint: find a one-named musical group). Oh yes, Nickelback!
The puzzle's title, "Reverse-Engineered Material," hints at making (or engineering) something by going backwards (or "reverse"). If you read the 5 longest Across answers backwards, you'll find 5 numbers spelled out within them:
17A: XENOMORPH > HPROM(ONE)X
21A. KOWTOWED > DEWO(TWO)K
38A. TAXISERVICE > ECIVRE(SIX)AT
55A. BROKENIN > (NINE)KORB
61A. CABINETRY > YR(TEN)IBAC
Add those numbers--1, 2, 6, 9 and 10--to form (or "engineer") the number 28. 28 is the atomic number for the element nickel, which is a metallic material. And that "nickel" is formed (engineered) by going back through those Across answers, pointing to NICKELBACK, a one-named rock band that satisfies the puzzles hint.
Admittedly this one wasn't as rigid mechanics-wise than others I've done. My thought was, "If you can think of what 28 might mean, and the pair that with the backwards part, that might lead you there." Thanks for giving it a go!
Meg 2s · 2024-12-03T03:46:06.210Z
Got some help from Ben. In the .puz file the clue for 52d has "across" instead of "actress".