Several incidents and questions have come up regarding the obligations of a boat that tacks immediately after rounding a leeward mark to port. I think most of it is clear, and I think I have resolved the last question for myself. But I am interested in the opinions of others.

Scenario: Two boats on Port gybe approach a leeward mark to be rounded on port. Yellow enters the zone several boat lengths ahead of Blue and will be rounding and tacking to starboard while Blue is  entering the zone heading to round such that they are on collision course at position 5.
Some easy parts: 18 does not apply (18.1a3). While tacking, rule 13 applies to Yellow and she must keep clear until born off to close hauled.
My question involves rule 15 and my uncertainty derives from USA Sailing appeal US52. That case found that a boat initially to leeward, gybing to starboard is right of way throughout and therefore rule 15 does not apply. However, there is no rule equivalent to rule 13 that applies while gybing. My interpretation is that a boat tacking from leeward to starboard is subject to rule 15 because she is the keep clear boat while rule 13 applies. Her position as starboard is a newly acquired right of way.
Through the course of the event I am considering, Yellow goes from clear ahead (Positions 1-3), to leeward (Position 4), to starboard (Position 5). But Yellow is the keep clear boat during the tack. So I conclude that she is subject to rule 15 as she completes the tack. 
She must initially give Blue room to keep clear (whatever "initially" means in the extant conditions).

Any opposing views?