I've found that tilting the guide so the saw side is lower helps a lot. The saw then has to pull itself up to the log and is not bearing against it so hard.
I'm not sure I'd ever bother to screw a plank to the side.
I don't have wheels and don't really want any.
I'm just brain storming.
Brain storming is good, we need more brainstorming, how else can we call ourselves milling geeks unless we brainstorm?
Here's an example of a log with one side being all lumps and bumps and the other being relatively smooth.
When we oriented the log we deliberately chose the smooth side of the log to be on the left when facing downslope. Luckily we access to a tractor with forks.