Yes they are but you need to wire them a little different. The HR20-100 can not power the DECA module on the SWiM tuner port. You need to split the cable running to the HR20 and plug the Deca module into tuner 2 and use band stop filter and run a line to tuner 1.
I was lucky and had the setup prior to the techs understanding this and they swapped my HR20 with an HR24 at no costs.