I also do lots of other DIY electronics.
For audio amplifiers, and circuits where ground loops can cause some very undesirable things, particularly since there are a lot of places that can cause ground loops in audio equipment, it seems to be pretty standard practice to have an isolator between the DC ground and actual earth.
I have built a bunch of circuits from Eliott Sound Productions, pre-amplifiers, signal processors, and audio amplifiers. I made quite the sound system with his circuits.
In this schematic, you can see in the bottom, the parts used for the loop isolator. D1, D2, R1 and C1 are all in parallel providing a nominal break between earth and the DC ground. This one is for a dual amplifier supply, but shows that the AC earth should have at least a modicum of isolation from the DC ground. This is also true for single-rail supplies. Failing to do this can result in audible noise in audio circuits.
If you omit D1 and D2, this will still work as an isolator, however should a large potential build up, you might end up burning R1, which would normally be a 0.25W device. The diodes protect R1 by acting as a dead short for voltages above the Vf of the diode, typically a bit under a half volt.
The Meanwell diagram seems to only use C1. This is probably adequate if there is no electrical fault elsewhere, but we're doing this in case there IS a fault elsewhere.