Off the top of my head, I would think you have to be careful about the load rejection and fast loading capabilities of the diesel genset. If it is a new recloser you can program whatever time you want for the reclose. This can then be coordinated with the genset limitations.
The genset will probably not have a problem with the load reject. Hopefully the system was spec to handle a complete load rejection. The real limitation is on how much load it can pickup rapidly.