Originally Posted by DeadGrandpa

FWIW, I also have a 1x ten speed with an 11-42 cassette with a Shimano Deore Shadow RD, although mine is labeled RD-M592. It was originally servicing an 11-36 cassette, which I replaced when I began riding in the mountains. Although Shimano rates the derailleur only for up to 36 teeth, I had zero problems adjusting it to accommodate the 11-42, and I didn't need or use a Wolf Tooth Link. I simply adjusted the B-screw and the indexing, and it's been excellent. I question whether you really need such a link when you install the new cassette. An unneeded link could add unneeded flex, but I'm not an expert. Full disclosure: my ride is an ICE recumbent trike, but it's a straight forward mtb cassette, derailleur and bar end shifter. Please report your installation results.