The artboard and shapes could be more versed.

[Bruno Henrique]

I would like to create custom weeds by values (pixels, cm, mm etc...) sometimes I want to create artboards in full hd resolution and another in 4k, it would be cool to be able to create shapes by numerical values as well, and the possibility of converting rectangles into artboards, this would speed up a few clicks.

[walt.farrell]

18 minutes ago, Bruno Henrique said:

it would be cool to be able to create shapes by numerical values as well, and the possibility of converting rectangles into artboards,

1. You can (kind of) create shapes by numerical values. Create the shape of any convenient size, then use the Transform panel to make it the exact size you want.
    
2. You can turn any shape into an Artboard already. Select the shape, then select the Artboard Tool. In the Context Toolbar, set the Size to Selection, and click Insert Artboard.

[Old Bruce]

20 minutes ago, Bruno Henrique said:

the possibility of converting rectangles into artboards,

Use the Move tool to select the rectangle and move it to where you want a new artboard to be. Switch to the Artboard Tool and use the Selection in the menu. You'll get the yellow rectangle as an artboard

.

[Bruno Henrique]

I used this possibility a little before writing this suggestion, but the more possibilities the faster and more intuitive affinty designer will become

[Pšenda]

23 hours ago, Bruno Henrique said:

by numerical values

Artboard Tool, draw Artboard, Transform panel - set numerical values.