520s will do just fine. I have XT M8100s on the good bike and yes, they are nicer looking and slightly lighter, but I picked them up for about half the price they are now. Wouldn’t pay the current 80-odd quid.
I had a pair of 520s that did 8,000 miles and were still in almost perfect condition. Gave them to a chap who bought a bike off me and they are still going strong. Think I paid £15 for them. Even at £30 they’re a bargain.
The trail cage ones help protect the mechanism and make it slightly easier to clip in when you’re hurtling down steep stuff, at the expense of a good chunk of extra weight. OK for a trail bike, pointless for a gravel muncher.