(16 days ago) Exactly the same as yokosooo: can get to 238, but can't see anything shorter, atm. Will be back! :)
Great puzzle!
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EDIT 1, 2022, 31st Dec, I have now found dgriff's 210. Not sure how to cut 6 more. Will keep looking.
EDIT2: Got it! This was really enjoyable to search for. And very well hidden, too!
I like that there is a vast choice of plausible blocks to be used on both side. For that level, there is no specific trick: it's really only a matter of choosing the correct blocks.
Seems like I finally learned hole filling around loopy structures like this. Got to 152 pretty quickly and took about 5-10 minutes a piece to cut each of the last 2. Definitely was confident in where I was losing steps here more than usual in a checkerboard.
146 update: the last 2 was a really good/sneaky cut. Thankfully it wasn’t really my pipelining because I felt like there wasn’t anything else I could do with it when I had 148.
Insights