BWP down to $3.42 and NPR at $1.34 means no arbitrage to speak of.
Possible scenario is that shorters move on BWP forcing both SPs down.
Longer term it comes down to the value you place on the merger- if the SPs decrease in the short term due to shorters, if that does happen, then that could be unwound post merger and the fundamentals kick in again.
Watching closely- not tempted as yet.
IMHO DYOR