Tamsin,
Thank you vey much for the suggestion. I have used textured beds for rendering and agree it it works well. I do think that there would be many advantages if we had greater flexibility by setting hardscapes with actual dimensions including thickness on site models with the prescribed slope. I think that it would be advantageous for sections, details and streamline the workflow process. I am an advocate of producing drawing that reflect actual site conditions. I will continue as you suggested. Always helpful!
Thanks,
lm