To your last point I can't see the use of "poleing" your screacher to leeward - it's a light sail that should set and take the proper shape without the pole, and in fact the pole would likely affect the trim in a bad way.
The use of a bridle is, as you say, common on spinn poles. They are usually end-to-end and avoid the high bending moment that can occur at a single point attachment. With an extendable whisker pole, an end to end bridle will vary in depth depending on the pole length setting. The loaded bridle will also tend to collapse the pole length. Perhaps this is part of the reason for Forespar's comments.