I was using the scale layer when I noticed a possible inconsistency.
The Amount attribute is, by default, set to 0, which leaves any layers underneath it at their default scale. When I set the Amount to 1 the layers double in size.
It is my opinion, backed by what I see in other programmes, that this is inconsistent with how scaling works.
In other “creative” programmes that I use every object is, by default upon creation, at 1 scale. So, at 2 it would be double in size and at 0 it would be invisible (i.e. just reeeeeally small).
Should the scale layer in Synfig work in the same way?