Correct. Well - not quite. PWBROWSER is still the first/default app specified in GINSU.INI.
I also edited DRMSTRT.HTM and DRMCST.HTM in the PWBROWSER folder - I know that one of these two is called up first, I couldn't be bothered to find out which one so I made both identical
Anyway, I put a meta refresh tag in the <head> part of the page to cause it to reload itself after 2 seconds and, as it does so, start Border Down via the x-avefront://whatever thing instead of loading the start page again. Works perfect.
If you want, I can post my GINSU.INI and DRMSTRT.HTM here.