I am hesitating as for where to place it, perhaps it could be more appropriate in the Issues, but I will give it a try here.
Looking at one recent problem [Update parameters in ModelingToolkit using callbacks] here at Discourse, I noticed that the old issue that we discussed here still persist:
julia> states(sys)
3-element Vector{Any}:
model₊y(t)
myController₊integralError(t)
myController₊manipulatedVariable(t)
So, was it finally decided to keep the ₊ as the separation character after the issue was closed?
Note also that in the legend in the figure https://global.discourse-cdn.com/julialang/original/3X/3/e/3e3d1d70af56d0610bd595aa51e64cd0e8eae60a.png in that post, some entries use . and some ₊.
May I kindly attract @YingboMa 's attention to this? Many thanks.