Read this very carefully.
You can load 1.5 software on custom firmware.
All you had to do was access the recovery menu holding R and switching it to the 1.5 kernel with the press of the X button twice.
Then using my previous method, you can debrand your
PSP PERMANTELY without devhook.
After that you can coldboot your
PSP at any time and play the current games or homebrew without launching anything.
It's the best of both worlds with nothing in between.