As a layout tool the Axminster device seems to fit accuracy-wise between an adjustable set-square and a vernier or digital caliper.
I don't do much layout with blue and scribing, preferring mill-table and DRO, but when within about 0.5mm is good enough, especially woodwork, then out comes my adjustable set-square. This example scribes a line on felt tip 50mm from the end of the steel flat:
Same result as the Axminster tool, but the Axminster device is handier and should be more precise because it has a vernier. The Axminster isn't as precise as a digital caliper in this application, but must be less fiddly.
I reckon an Axminster would be well worth owning if a lot of laying-out was being done. Otherwise, a caliper and adjustable set-square will do the job and can be used in other configurations.
I expected to get a lot more use out of my adjustable set-square set when I bought it, and invested in a large bottle of layout blue and a Height Gauge. Not a waste of money but in practice, I don't have much call for any of them.
How much marking out do others do?
Dave