type checker plugin success depends on whether an expression is manually inlined

[adam vogt]

Hello list,

The following file compiles with my plugin. It makes a data family
HList have role representational in a way that I believe is safe:

https://github.com/aavogt/HListPlugin/blob/master/ex/Coerce.hs#L19

I expect the highlighted line to be acceptable. However, it seems that
the plugin never sees anything from line 19, when I uncomment it. Is
there something I can do to make that L19 work? Is this a known or
intentional limitation of type checker plugins?

Thanks,
Adam