This is a minor issue, but it it happened to me that I didn't notice that I was drawing a layer that was hidden.
I made a lot of rectangles that "disappeared" and I didn't understand why.
I think it might be good to avoid this issue.
Some possible solutions I can think right now:
if you want to avoid it: an alert popup or message once you start to draw a hidden layer (some drawing programs do this) letting you know you can't do that
if you want to let them do it: once you start to draw, some small message window (like a tooltip) by the mouse, or some text below the drawing window appears, warning you that what you are drawing wont be visible
This is a minor issue, but it it happened to me that I didn't notice that I was drawing a layer that was hidden. I made a lot of rectangles that "disappeared" and I didn't understand why.
I think it might be good to avoid this issue. Some possible solutions I can think right now: