Ran a test on a echo 50cc once years back. It loved 3/8LP and 325 but did not like FULL 3/8.
So why run something on a saw to be all the same in 3/8 is just stupid IMHO. When the saw clearly cuts better using 3/8LP or 325.
Have a sign on my bench I point to when needed sometimes.
Bill is not the first I've seen running (with success) full 3/8 16 inch on an 026. If it ain't broke, and works well for him, more power to him. There are advantages and drawbacks to all chain. And of course a best fit for a saw. In the US, Stihl says that's 325 for most 45 cc saws. In Europe, they say 3/8 lp it seems. I sure like the LP on the ms250 with a 16" bar. Can't slow that little saw down.