I think I got pretty lucky here. Spent a couple tries feeling out the level, and then my first solid attempt at some shortcuts gave me a 255. Next try I found the remaining 2 and got the 253. From the sounds of it there are some other close paths so I'm happy I was able to avoid those.
Amazing how many possibilities there are in this level. The best I could do was 8 off for the longest time, then finally broke through to a 241. From there I still had to iterate quite a bit before landing on the 239.
Insights