I know, I'm a little late to the party. I just haven't had much interest in the Shield/s. However, the clerk at the LGS handed one over to me to check out.
That's the immediate impression I got, that it's the .45acp frame platform with a double-stack 9mm mag in it.

?

No, they are different.

Attached Images

IMG_20220119_095002057.jpg (193.2 KB, 70 views)

That biggin' looks like an M&P full-size, LOL. I meant to say, is the Shield Plus built on the SHIELD .45 frame. Thanks.

No. Try to put a Shield+ mag in a 45acp Shield. It doesn't fit.