"Bypassing" the throttle body is well discussed in this and other Rover forums, but many forum members explain it in a way that is more difficult than necessary to execute.

The throttle body coolant lines need only to be plugged. Coolant does not need to be able to flow through the lines. The RAVE illustration makes this clear; coolant from the throttle body heater lines does not supply or support any other purposes.

All that's needed is to plug the two hoses that attach to the throttle body heater. The heater itself can be left "open." I've used two appropriately sized cap screws (i.e. bolts) and hose clamps to do the job. No U-shaped tubing or pipe is necessary.

 

I think the bent u shape is widely used because it's so readily available. Piece of 1/4", laying around, and bend it.
I actually have a solid piece of 1/4" solid aluminum rod.... I like how the u shape keeps my hoses together and in place. But what ever works.
You can also get small ****** brass plugs that fit perfectly. The are pex fittings in the hd plumbing isle

 

It's just as easy to connect the two together and allow it to flow. Seems like to me pluging them would make an already PITA cooling loop to bleed of air even more so a PITA by allowing air pockets to form. No contest to just leaving the plate open though. I did mine.