Layer "lock"

[GalaTepes]

Dear affinity staff.
I was wondering if you would be so kind to create a layer lock as the photoshop. It happens that constantly generating layers and layers is tedious. It is easier to paint over the area of the selected layer without leaving the "edge", (I feel like I have returned to kindergarten), and without the need to be generating groups of layers.
Thanks for your attention. Have a good day.

[MEB]

Hi GalaTepes,
Welcome to Affinity Forums
In the Pint Brush Tool (and other tools as well) tick the Protect Alpha box in the context toolbar.

[GalaTepes]

Thank you sir. Have a great day.