surely this will be the last release

If you do it right your SD card should have this folder structure:

SD
  apps
    Nintendont
      boot.dol
      icon.png
      meta.xml
    Nintendont Forwarder
      boot.dol
      meta.xml
    Nintendont Slippi
      boot.dol
      icon.png
      meta.xml
    Nintendont Slippi Forwarder
      boot.dol
      meta.xml
    NintendontForMelee
      boot.dol
      icon.png
      meta.xml
    NintendontForMelee Forwarder
      boot.dol
      meta.xml

1. Access the Priiloader menu by holding the face RESET button when powering on
2. Load/Install File > the appropriate forwarder
3. Settings > Autoboot: > Installed File

probably the last release?

Download forwarder.zip!

So slap this forwarder in your apps/ folder and set Priiloader to autoboot it instead.
It forwards to apps/Nintendont/boot.dol, which should be where you installed Nintendont.

If you do it right your SD card should have this folder structure:

SD
  apps
    forwarder
      boot.dol
      meta.xml
    Nintendont
      boot.dol
      icon.png
      meta.xml

I extracted this .dol out of Badablek's forwarder WAD, listed on the GBAtemp Nintendont page.