Christopher Rackauckas

Are you not counting the observed equations?

Yes, since connections can be more than one equation.

Why is the description cached?

> Compute it on-demand with a function? Yeah make getdescription just a function that computes it, and call that during `show`. I could foresee it being nice if `getdescription` returned...

> I think that's less intuitive than passing just a string. Oh I thought you were saving the whole description 😅 . I see, if it's just a string that's...

This is the right direction. Let's go with it and see how it feels. It might need some adjustments but any minor changes I won't know until I've seen it...

`__similar(x)`, why are we not just using `zero(x)`?

> I think get_tmp in PreallocationTools.jl doesn't support BigFloat and would cause cannot reinterpret `BigFloat` as `ForwardDiff.Dual`, type `ForwardDiff.Dual` is not a bits type error, similar issue is https://github.com/SciML/PreallocationTools.jl/issues/72 We...

I don't understand the need for `__init_bigfloat_array!!`: aren't you always building BigFloat caches now even if you don't use BigFloats? Why isn't this a part of the DualCache? Can't you...

https://github.com/SciML/PreallocationTools.jl/pull/112 should be all you need?