Will the LBRP conflict with spirits you are trying to call forth. If invoking gabriel for example and then wanting to evoke lucifer, will this cause any problems?
Although the LBRP may be seen as a RHP JC concept, and therefore counter-intuitive to use with darker energies, this is not my experience.
I see the ritual as a way of encouraging (invoking) or banishing elemental energies. I focus far more on the element of the quarter rather than the origin or personality of the godform.
I would naturally be evoking in the North for Luciferian magic, although some may see the east as more appropriate.
As others have said, the purpose of banishing is to clear the area BEFORE you begin to evoke, but again I see no problem in invoking the lords of the four quarters for their elemental assistance before you begin the ritual proper, so long as you banish at the conclusion.