I am installing webmin and virtualmin on a new set of machines. Currently we have several sites that use ColdFusion.
We have stopped developing in ColdFusion so I do not really need support for it. If there is no support then I just won't migrate old sites to the new system.
The support we are looking for includes things like managing the database connection files. (It's been a while since I personally dealt with CF so I don't recall what all we needed to do when setting up a new virtualhost.)
I googled and found "Bug #35: ColdFusion features" but it looks like it might not be done.
I did not see any webmin modules for CF when I searched at http://webadminmodules.sourceforge.net/?page=Search&action=search