You can create all kinds of amazing bobbled / jagged / rough / circle 3D dashed line designs in Affinity Designer by using the dash features with strokes. Select the pen tool and create a basic stroke
Go to the stroke settings along the top toolbar and then set to dash style (don't worry about the settings at this point) You can set any combo of 1-1, 0.2-0.2 etc if you wish as well as set a width / weight for the path
Go to the contour tool found in the tools panel and drag outwards to create a filled contour. Go to the layers panel and go to the bottom 'fx' and add a layer style such as 3D as well as shadow.
Have the same color for the fill and stroke so if you have gray for one, use gray for the other.
Go to the stroke panel again and style and change the settings as well as the joins / cap etc to create all kinds of unusual jagged and bobbled and spiky artwork and it is still live so you can always go back to it and change at any point. You can add this style to all kinds of other paths as well. Go for 1-1 or 2-1 or 0.2-0.8 etc, vary them to create all kinds of unique combinations and also change the joins etc as well as that create different designs.
55pt, round, outside, 1-4
55pt, round, outside, 0.2-2
55pt, butt, outside, 0.1, 3
You can create many different artworks using this and you can also go to the node tool and add additional points as well as tweak the design into all kinds of different shapes to create wonderful frames, borders, enclosures, abstract artwork and more