I don't.
However, here's my take on extensions in general.
When I put them (one two round and one three) on my "Serious" 870s, I was big,strong, and healthy. Swinging a 9 lb shotgun was child's play.
Now, in my declining days, a lighter,more nimble tool makes sense. I can still handle the heavyweights, but I can see the writing on the wall.
Extensions have other advantages besides more rounds at hand.
The weight out front helps keeping the muzzle on target and cuts recoil a bit.
Those 9 pounders do not kick very much.
The other advantage comes with the clamp. Proper clamping can halve slug group size.
A 1 round extension will add maybe 3 oz empty to the O/A weight. That can help handling, but so much depends on the shooter.
Besides my two HD 870s, Frankenstein( my parts 870) can be considered as a HD candidate here. No extension, and stoked with 4 buck simply because I have plenty. I added a 3 oz weight to smooth the swing out some. Handles well, for me. And it's faster than the behemoths.
Let me close with this. A 1 oz extension is a possibly worthy add on. So are bigger ones and so is none.
Find out what works for you and go for it.