Have you looked at the grass that Desert Mountain used for Renegade and Seven? What do you think of it if you have? My impression is that it has held up well through 2 summers and last summer was high stress. I was told it's a bent variety. Desert Forest used to have bent fairways a long time ago - maybe it's a modification of that?
Desert Mountain is a fantasyland for how they manage turf. Having a crew of 30-35 guys on each course, plus having extended closure times on each course makes it a different ballgame.
Regarding Renegade and Seven, they are doing bent grass fairways with fescue rough, this only would work in north carefree which it is located in due to the higher elevation and cooler nights in the summer time. There is no way a property could do that in the valley. Also it requies a ton of water to keep it alive during the summer, hence why they close it down from July-August. They also have to spray wall to wall fungicides to prevent disease pressure. Both of those things cost a lot of money, something a VERY high end private club can do, but that is about it. They also have 2 courses that are at the top of the mountain that they just hold onto the Rye year round and don't even bother with transition since it is cool enough. I think they are only overseeding 3 of the courses now, as opposed to all 6 in the past.
I am surprised no one has tried zoysia out here yet. We had a test plot of zeon zoysia when I was at wickenburg ranch and it held its color throughout the winter even up there. That seems to be the best option IMO for a turf that doesn't need to be overseeded.
With regards to water with salt water, TRUST ME we already deal with a ton of salts with hardly any rain. There is no way we could grow grass out here if we did that. I water with reclaimed water that already has salts and chlorine in it. We went 15 months without any significant rain from 2020 to 2021 and all kinds of guys were getting hit hard with rapid blight, which is caused by salt loads accumulating from not having a good flush of rainfall.