What kind of trouble have you seen?

I would be interested to hear more about this. It's a subject that deserves attention from time to time, to ensure that we do not become complacent with the status quo of dursos and valves.

I wonder what Bambrose did to resolve the issue?

If youi put a valve on thr drain side you are asking for trouble.

after much research I found that if you put a tee fitting on the end of the hose in the sump and run the tee above water the bubles escape without all the gurgling noises and the water just runs in the sump. you can even move the tee to the surface of the sump level but you should keep the end extended in the water.

Yes, a gate valve near the bottom of the return to the sump will allow you to adjust falling water so it backs up and the small bubbles have a better chance to rise back up the tube and not be pushed down into the sump.

In addition, you could place a floss bag over the end of the pipe which usually stops all bubbles. (until the bag is clogged with crud and overflows.)

Alternatively, place a 1-2' length of corrugated pipe (bilge pipe) after the second 45 before the first 90 and let it curl around in the sump area. The corrugation slows the flow and releases the bubbles in a less noisy fashion.

Alternatively, place a much larger sponge or more sponge at the bottom so that all the water has to flow through the sponge to get into the sump. This will slow the water, allowing bubbles to be released but it will also require periodic removal and cleaning of the sponge.

In my tank, I have Chaetomorpha algae as a living sponge at the end of bilge pipe, but you are not using this as an RDP so that option is out for you. (There is inexpensive white plastic bilge pipe at some hardware stores that slips snugly over 1" pvc)

Hope this gives you some ideas.

Several things could work. Would need to see the sump to know for sure, but it may need a valve which backs up the water in the pipe to reduce the mix of noisy air coming out the end.