Keep up the hard work OP. Nothing wrong with a clean set. Managing your game is essential and clean sets are evidence of staying under control. When you run into difficult conditions, leaving makeable spares and actually making them goes miles!
I always have (and recommend) plastic at all spare attempts that do not contain a sleeper. Going straight is simple, eliminates the condition, and you just have to reach towards your target. Namely with single pins, I line up with the 4th arrow and reach thru it into the pin. No matter what I run into, this is always the same and I'm become very comfortable with it. I honestly couldn't imagine shooting left side variations by hooking the lane on flat patterns in transition.