It would be great to have an option to export a point cloud with classifications. This would enable users to filter the point cloud by classification.
Just throwing it out there, but I use Carlson Precision 3D Topo to classify and DTM the DroneDeploy point clouds.
I would suggest Global Mapper with the LiDAR extension, which includes Pixels-to-Points tools. You can classify drone derived point clouds as you would with unclassified LiDAR points. Works quite well.
I have found it much easier to classify the point clouds while going through the DTM process. Separate point clouds are created as the filters are run which makes it very easy to get a precise classification using all the points. It is very common specifically with Photogrammetry their are allot of outliers when dealing with structures and vegetation and while we only demo’d other point cloud management softwares I would consider P3D Topo and true point cloud editor. The draping functionality and CAD integration is very strong. I know it costs more, but if you are into serious drone photogrammetry mapping it is the only one I have found so far that is consistent and most flexible on the configuration of the filters.
That said I would definitely recommend Global Mapper as a solution for an almost complete workflow for this type of data for people that do not deal in the CAD realm. QGIS is just as functional, but you do not get the level of support that you do with Global Mapper.