Yes, you can still use Sefaira. Most other architectural design applications support export to SketchUp, or to open source 3D file formats such as Collada. These files can then be imported into SketchUp to be analyzed with Sefaira.
HOWEVER, keep in mind that models will only analyze properly if they are modeled in accordance with our modeling guidelines (link here). Typically, models that are imported into SketchUp (from Rhino and ArchiCAD especially) contain triangulated geometry, wall/roof/floor thicknesses, extra geometry unneeded for the analysis, etc.. . You may need to significantly simplify an imported model or group the imported model to redraw a Sefaira analysis model over the imported geometry similar to the workflow described in this video (link here).