Seems to work just fine!
I installed my Barrow 3090 MSI cooler a few hours ago. Temps have dropped when running various benchmarks from 60degC to 32degC with a couple of 240mm fans. Idle its 5 over ambient on my setup.
The instructions are vague at best at times, but I muddled my way through. You are going to have to remove a support bracket that isnt mentioned in the guide and I added lots of thermal pads to exactly the same place as MSI did.
Also I never used the screw pack supplied, just in case you are wondering what all these left overs are for ..
Hope that helps someone!