Need a bigger cassette but derailleur is at advertised max capacity (yeah, it’s Shimano so I can push it a bit…)

Anyway, Wolftooth are 4x the price of the Amazon copies. At the end of the day, it’s a small ALU beam and two threaded holes…

I’m assuming my derailleur is NOT direct mount. Correct?

I can’t speak for the quality of hanger extenders other than to say that personally I don’t really like encouraging the endless Amazon knock offs.

You’re right about your derailleur though, that’s NOT direct mount.

This is direct mount (not my image or bike).

The cheapo eBay/Amazon ones work just as well as well overpriced wolftooth ones, bought a road link copy and the longer CNC’d version for a few quid off eBay to experiment with a mates old bike, they work perfectly, impressed by the quality of the CNC’d one, why pay more.

I’ve used the cheap ones which work but often a softer alloy which can be bent too easily putting indexing out.

At the end of the day, it’s a small ALU beam and two threaded holes…

You already answered yourself.
fooman

I’ve used the cheap ones which work but often a softer alloy which can be bent too easily putting indexing out.

Yeah it’s a sacrificial part to the sacrificial part… 😉

Used a Sunrace very successfull with 9spd ultegra.

https://www.merlincycles.com/sunrace-rear-derailleur-extender-link-134836.html

there’s airbike too

CNC Derailleur hanger long extender Goat Link Race Link Mech Range expander LONG

I’m using an Airbike one and it works fine.

I put a cheap ebay one on my lads bike a few years back – still going strong.

I picked up an Enlee version of the Airbike one above in purple for £3 inc free p&p, eBay cheapo from china but CNC’d from seemingly good quality grade billet, it works great with 46t cassette, ridiculously cheap but took about 2 weeks to arrive.

They are different lengths though, not sure how much difference that makes and struggled to find out.
Eg the Air bikes one is marked as ‘long’ and is longer than the one in OPs photo.

Assume different lengths are for long/medium cages?
I got the Air and while it works, seems to be a lot longer than I need and engagement is a bit off, so have ordered a shorter one to see what difference that makes.