I do that when the budget allows. I have programs for that sort of thing. It requires a billet manifold, or one of Jay's "higher than a High Riser" bases, and then a fabricated spider. It also requires relocation of the bar to get the geometry to work right. Sometimes it is better to just make a new and altered subplate for the T&D.
It is better to raise the roof, for several reasons, but it gets expensive in a hurry. Last year I designed an intake port that will fit within the Medium Riser valve cover, and can work with a reasonably modified cast BBM tunnel wedge. It only missed the extensively raised port by 7-10 cfm. There is more going on than just flow, but made a lot of power, and we got within about 40hp of the raised port/billet tunnel ram, with a high Medium Riser/modified BBM cast intake. My opinion is that for the cost/benefit if it, most of my Pro Port customers will choose the Race MR Pro Port and cast intake, if they want more than the Street Pro Port can produce. Those who want the "max effort" will still go for the high port, but not many.
The cost of working the intake manifold, and moving the pushrods on any of the "other than stock" locations is a factor. It is possible to get to 800 hp with compression, using ports that are only 1/8" taller than MR location, and 1.400 wide in the stock side-by-side position. The point being that the vast majority of an end user's goals can be reached WITHOUT relocation, expensive intake mods, and offset rockers. I reckon it just depends on what the goals are, and what the budget is. The right camshaft for the use, and an efficient, fairly stock location port can do pretty well if the port is made right, once inside that stock flange location. For .600 lift or less, the benefits of raised/moved ports are minimal. The LS intake port in the Trick Flow head is very good for the money. They are a little small in some places for 482+ cubes. I have fixed a few sets of these, and end up with a little less cost to the customer than the Street Pro Ports. I can get the intake side almost as good, but the exhaust side and 1.625 valve still lacks a little. Seems like no matter how we go, it is still a "get what you pay for" situation. I think I may be rambling now......but back to the original post......for most applications, the really high ports are not worth the cost difference. At 482+ inches and .700 lift + solid roller territory, a relocated MR height can really work. Only the really serious apps will warrant raising ports past what a MR valve cover rail can house.