Respect “Fill all shapes” across separate layers?

LB 1.4.04 GRBL on Win10 via USB.

Not sure if I’m missing something, but I have been able to set up any project with multiple fill layers, all set to “fill all”, so that it scans all layers in one pass.
I can achieve this if I flatten the fill layers into a single layer.
For example, I have four fill layers with the only difference being power. I set them all to 100% power, edit the power scale to my desired intensity, select all, then collapse all into a single layer.

Unfortunately, this makes editing power rather difficult if the design is sufficiently complex.
I can cut my job time in half by doing this, so I suffer the edit difficulties, but I would much rather have LB respect the “fill all” setting for all layers of the same type. I can understand layers of different “cut” types demanding a separate pass, perhaps even those with differing speeds. But, if the only change is power, the effective combined result is identical to a grayscale image scanning process, no?
I understand I could create the design as an image and just use grayscale or passthrough but I like having objects retained as paths/vectors for edit flexibility and having more absolute control over power.