[NTG-context] [***SPAM***] Provide showgrid as a PDF layer

Dear All, it would be nice to have a possibility to interactively disable/enable a grid rendered via \showgrid command. Whereas this grid is helpful for debugging, it disturbs when the page is evaluated as the whole. Using layers could make this process more efficient (not requiring to generate both variants). I've noticed something like this is already implemented for the body area (visualizer vbox layer). Or is there any option for this already? Thanks, Jan