Hello and welcome.
I changed 2 standard 1.2 Daro tanks. First one with skinny overflow, second with good old standard corner box.
First mistake,on first tank I made the overflow right in the middle at the back of the tank. Directly under the centre cross brace. Yes, that was stupid in hind sight. A small snail went in there, got stuck, died and created this wonderful waterfall sound. And there is no way that I could get anything in there to be able to get the snail out. Secondly, its too narrow. Must be at least 200mm wide.
Second tank, with standard corner overflow box. Is a lot better. Easier and with standard Durso standpipe, a lot less noisy.
First buy the bulkhead before you drill the tank. Else you might find that you cannot fit the bulkhead later.