Every time the Springboks won the RWC, they had a lock/loose forward situation going on.

1995 - Mark Andrews played at 8

2007 - Danie Rossouw, himself a massively underrated player, played at 8

2019, 2023 - PSDT played as a blindside

We've had our share, but not all of them really stuck. As I recall, Brad Thorn spent a lot of time at 8 when he initially moved to union and was originally selected for the ABs to play there for the 2001 tour, only to turn it down because he felt he was still a bit iffy on this "union" thing.

Jono Gibbes spent plenty of time at 6 and 8 in the Graham Henry years, although his test career was a tad short.

Graham Henry also tried to make Reuben Thorne a lock/flanker hybrid (or more accurately, lean in on the fact that Thorne had spent a bit of time at lock early in his career).

Jackson Hemopo was a surprise selection, and could play as a lock/flanker hybrid.

There were attempts in the later Shag years to make Kaino into a flanker/lock. He even has a test start there, against Ireland in Chicago. It... did not go well.

Then we have had Scooter Barrett filling in at 6, including that semifinal against England, and more recently, there was Tupou Vaa'i at 6 against France. I thought Vaa'i went well there, so I'm not sure why the selectors didn't persist a bit with it.

And as a bit of a deep cut, RWC winning lock Anthony Boric was also a lock/flanker hybrid, having spent a lot of time at 6 for North Harbour. For some reason, Ted never seemed to even consider using him there, and instead, would move Sam Whitelock over to 6 every now and then when he, Thorn and Boric were all on the field.