RDKit: Murcko Scaffolds - Feature Request

The Murcko Scaffolds node is quite a neat way of gathering together common cores or fragments in an SAR and can be really useful to check for diversity.

Is it possible to have some additional options such as:

- discard any unsubstituted rings, i.e. if any ring is only monosubstituted then it must be terminal, and therefore may well not be part of the key fragment.

- discard unsubstituted rings which are x membered rings (i.e. this is useful for removing cyclopropyl and cyclobutyl rings which are often used as substitution groups rather than part of scaffolds acting as spacers). At the moment, having these present in the Murcko scaffold output can severly skew the diversity of the fragments.


Otherwise this is a very nice addition to the every growing uses of the RDKit nodes.