
stuff like that ?
have a first line of dimension, then a second line that “adds” them ? then yeah, no “duplicate tool”, you’ll have to remake the new dimension by clicking on the same inferences points as the first.

in (my french) layout, if you right click the paper space, you can either snap to objects or grid. or both.
by snapping to objects, you can place dimension on the SU actual points (seeing your screenshots, I’m pretty sure you already know that but hey, others might not)

so yeah, to make the two 450 dimensions, you clicked on the points I marked green. and to make the 900, you’ll have to reclick on the top and bottom. no shortcut on this one. as long as you click on the same points, they should snap on top of each others.
yeah, I thought about it, and the best solution I’ve got is exemple 2, but line by line then. select a line of dimension, and stretch it. then select then next one and so on. you’re kinda hitting the limits of layout here,
SO was not created as a CAD tool but a sketch one, they added LO, and it allows you to make plans from a SU file, but still, it’s not as complete as the equivalent in an actual CAD tool.
same way, it’s not as complete as indesign, or powerpoint. It’s sitting at the intersection of the three, able to do a bit of every one but not actually 100%. that’s where the frustration usually starts.