The Roco rotated upwards inside the regular linkage at full compression. It snapped the shock shaft inside the coil, pretty disastrous!
Managed to find the last Evo linkage available from Specialized and went the correct route of converting to an Evo. Luckily the shock rotating didn't do much damage to the frame when it snapped! It was a fun experiment machining the notches into an aftermarket shock but much easier using the Evo linkage