This may sound way outside the box but way back when you first introduced Layout, I was conflicted with a while new set of commands and file organisation --not to mention the then challenge of integration between Sketchup and Layout...
Now 15 years on I suppose its all easier but its also getting easier and easier to replicate what you get in Layout --in Sketchup itself.
Minus such as the ability to control specific line weights and color in good detail, text placement--along a dimension string and a few others, you already are 3/4 the the way home with integration of both programs into one more comprehensive Sketchup program. Viz., good 2d projection and visualistion control, many 2d extensions, access to all types of rendering engines--and some initial attempts at least at line type, width control and colorisation...
I personally would really welcome such a move but please elucidate me on why it is either too too complicated and or expensive to now take the final few steps of integration of Layout into Sketchup as one integrated program.
You have argued that it would be too complex and expensive in the past but the continued explosion of good extensions seems to be closing the gap.
Thanks for your elucidation:
Richard Stanley
rstanley@mind.net