Mike,
I was focusing on the spline.
Josh,
It can be different in clay soil, but I think Mike's Wolf Point has as much clay as anywhere....at least most of that region does.
And then, you do what you gotta do. I try to keep them as low as possible, but the first thing to do is go out and survey the drainage outlet you are draining to, whether pipe, pond, or stream. Since your 4" drain pipe needs at least 1% to drain, if it is pipe in a creek or pond, and you are 200 ft from that outlet, the pipe invert at the low point of the green must be at least 2 feet above water level, and if using 12-18" of sand/gravel for USGA, the front of the surface that much higher.
You might leave another 6" just in case, meaning the that green has to be 3.5-4 foot about the outlet. If you happen to be in a flood plain, the green surface (and preferably the bottom of the green dish, if applicable, but likely in clay soil) should be at least an inch above the 100 year flood plain, so you fill to there. And, if you are doing any grass depressions that need catch basins, you need to figure their outlets, and then the relative depth to the green. In the modern world, you also need to be sure your green has at least one <5% approach for ADA wheelchair traffic, which of course, tends to lower the greens.
If that is still at ground level then you can build a ground level green. If it comes out that you need a foot or two of fill to get there, you put in a foot or two of fill.........
The open front does allow you to keep it low. If there are bunkers anywhere in front, they usually require similar math for their drain tiles, and 3-4 ft of depth, so then you need to create a fill pad if you want to see the green behind the bunkers.
Actually, between budgets, ADA, and the rise of public golf and the consideration of not kicking the ball far off the green with a steep slope, my guess is that the average height of greens above the fairway has come down over the last two decades and that their are plenty of "seamless" transitions from fw to green. Certainly a lot more than in the RTJ/Wilson era, when the "elevated green" was a sign of distinction.
Not that those moderate upsweep approaches to elevated greens, such as we found at La Costa, aren't attractive, if not ground game friendly. Maybe nostalgia, but I found them quite attractive, and would like to be using more elevated greens to create those, where possible. That said, my work is usually in the public sector, and in my last two renovations, there aren't too many truly elevated greens. Most are near fairway level.