I use this XLR rack panel for an amp rack. Soldered 4 Neutrik XLR (1 panel) and 4 speakon (2nd panel) connectors in it, left the others empty (spaced 2 apart) to keep some air flow going.
The XLR and speakon tolerances are fine and my neutrik female XLR and Speakon connectors fit quite well.
However, the panel has some flex to it. especially in the middle. I use this with 2 amp racks that are mostly for installation work, so connectors only occasionally need to be reconnected, for this kind of use this is fine. I can be careful when connecting or disconnecting cables.
If I was making a rack case for daily use, I would want something sturdier, that wouldn't flex. I would not trust this for the hard life on the road.