Work is currently underway to make this possible.
Glimpse is getting very close to a v2 RC, when that is released then we will also be ready to push out a release of the Glimpse.Nancy integration being built here https://github.com/csainty/Glimpse.Nancy/tree/glimpse-20
I can't yet comment on Mono support as I have not tried it, but I will make an issue to make sure it is considered.