Supply at least one Family that is scalable and can be hosted. Possibly a Generic Face based Family. Hugely popular seminars are being taught at Revit gatherings on this subject, it must be of broad interest. Creating logos and signs is a particular area where those who use Revit for commercial buildings would greatly benefit. Currently a workaround employs multiple nests of Planting Families but you still can't accurately identify the size of the object and must nest in other than Planting to host it.