Presumably, LS has been overlapped with WS for some time.
...
Anticipating a wind shift back, LS wants to enter wide and exit close so she sails the lift which now hails for WS to "come up".
What are options here for WS and LS?
To determine if rule 17 applies, you have to look at how the overlap was established -- no matter how far back in time that was. Not knowing that, I can't say whether or not the leeward boat may sail above her proper course.
That appears to be moot, however, because as described, it sounds as if the leeward boat doesn't sail above her proper course anyway. In that case, when L changes course, she must give W room to keep clear (RRS 16.1) and W must keep clear (RRS 11).
Am I missing something?
Regards,
Eric