Below is the best I came up with to get all output to one file, its dependent on the order of commands (specify report device first) and the "open file for append" on the prompt and progress commands:
#open with ISLCT = 2 for a file
psspy.report_output(2,outputname+".all.log",[0,0]) #set option (1) to overwrite for existing files. Must do this one first to write all successive otput with option = 2, open file for append APIv33 1.277
psspy.prompt_output(2,outputname+".all.log",[2,0]) #set option(1) to 2 for 'open file for append'
psspy.progress_output(2,outputname+".all.log",[2,0])
#all of the above written to the same file "outputname.all.log"
While adequate for simulation output, the above don't capture results of "DOCU" or "RAWD." IF anyone has a good writeup on PSSE output strategy, please share.