I would search GitHub issues (open and closed) before opening a new request there, just in case your usage was re-solved better there.
Here are my “best of 3” current solutions
Since SumatraPDF does not lock files under 10MB [UPDATE now 32MB in pre-release] you can simply substitute first.pdf with file2.pdf then hit R IF necessary to refresh (that’s the whole point of reuse, it should auto refresh, but depends on where your pdfs are, as some users have found the system does not see a remote overwrite)
so script wise for files seamless under 10MB [Or 32MB in 3.2 pre-release]
sumatrapdf.exe -fullscreen welcome.pdf
wait trigger
copy file1.pdf welcome.pdf
wait trigger
copy file2.pdf welcome.pdf
…
(optionally loop back to before file1.pdf)
The simplest use for run (& optionally loop) given list of files, including over 10MB [Or now 32MB in 3.2 pre-release] is to first set exit on escape in settings (EscToExit = true)
:start
call sumatrapdf.exe -fullscreen file1.pdf
(then when done hit esc)
call sumatrapdf.exe file2.pdf
(then when done hit esc)
…
goto start
It will close and reopen the window on second screen (depending how fast script and next call takes it may only be momentary distraction
Lastly DDE method DOES require Tabs enabled so all files are finally in memory for recall (via a menu ?) there will obviously be a limit per machine as to how many files (depending on their size) can be loaded. ALL files could be preloaded without a pause then be selected using a backend menu system
here is how it can work one at a time (without preload)
SumatraPDF.exe -fullscreen first.pdf
pause (or wait)
execdde (via whatever script engine your using) [Open(“second.pdf”,0,0,1]
pause (or wait)
execdde (via whatever script engine your using) [Open(“third.pdf”,0,0,1]
pause (or wait)
…
(optionally loop back, will run quicker second run as all tabbed files are now loaded
So now you have 3 options or a hybrid between them