I was looking at the report you linked to in regard to the SE5 and noticed it was from April 1917 which was around the time the type entered service and also noticed that at the end of the report in May 1917 that cutting down the wing tips increase the max G to more than 6.5 up to 200mph. Were these changes incorporated into the SE5a along with the more powerful engine?
Was doing some quick searching on google and came across this: "The first production batch of SE5s did not make a promising impression on their pilots, who complained of poor lateral control – a shortcoming that was alleviated somewhat, but never entirely, by shortening the wingspan and reducing the rake of the wingtips in later production SE5s and SE5as. Engine reduction and gun synchronisation problems also afflicted early SE5s." So it does seem the wings of production aircraft were modified at one point. Source: https://weaponsandwarfare.com/2017/10/30/royal-aircraft-factory-se55a/