I usually render at 2500 X 1750 the reasoning here is that it generally renders fairly fast and I can scale up to 4961 X 3508 with very little loss in detail.  Seems odd but at 300dpi that is correct for ISO page size A3.  Most years I do an A3 photobook with the work from that year and a record of, hopefully, my progress.  With the monitor correctly calibrated the printed page looks good and it forms a nice record.

 

 

I use Poser 13 on Windows 11 - For Scene set up I use a Geekcom A5 -  Ryzen 9 5900HX, with 64 gig ram and 3 TB  storage, mini PC with final rendering done on normal sized desktop using an AMD Ryzen Threadipper 1950X CPU, Corsair Hydro H100i CPU cooler, 3XS EVGA GTX 1080i SC with 11g Ram, 4 X 16gig Corsair DDR4 Ram and a Corsair RM 100 PSU .   The desktop is in a remote location with rendering done via Queue Manager which gives me a clearer desktop and quieter computer room.