i have big anouncement to make !
it was not working through a fw external partition where i wanted to restore/put the .iso boot image ... convinced that the .iso s were corrupt,
but thanks to stewc , i just burned the iso to
CD with toast , before i had CHRP boot error with cd in OF,
\\ tbxi cd: or something, did not work, giving the annoying chrp error, but i found a short-cut
multi-boot cd !!! and it booted smoothly for the first time (no disk with question mark) and went way along the mac os 9 boot route ... without manually blessing the system folder & system file(Mac OS ROM) in the system folder ...
(((
the main difference visually is Mac OS ROM system file in the system folder , when i was trying to put the 'Mac OS 9.2.2 for unsupported G4s' boot image on the external FW hdd ( a lacie porsche fw enclosure) was black, no icon/logo, therefore i sought to bless that file & the system folder manually in terminal ... which succeeded partially, sudo bless -folder '/Volumes/Mac OS 9/System Folder' did indeed bless it & created a BootX file in the system folder (sudo bless -info '/Volumes/Mac OS 9/System Folder')... but when restarting , do the OF(OpenFirmware) hacks like described hereunder:
dev /cpus/PowerPC,G4@0
80010201 encode-int " cpu-version" property
device-end
multi-boot fw
got stuck at at disk with question mark
=> conclusion: if you boot from the ISO you burned on CD, the system folder & Mac OS ROM system file will have its normal logos/icons & will, without needing to bless it manually, just start up the installation of Mac OS 9 : ) ! ! ! !
))))
So yeah after 5 days of sweating & crying & desperately staying up late, red eyes & what not
Mac OS 9 officially, i can announce, works with PPC G4 Aluminium Powerbook 15 inch ! 1Ghz
Hurray Hurray Hurray !

So tbh the booting of the first iso was the most complex for me
1) finding the right ISO
2) burn to CD
3) OF tricks ending in multi-boot cd
tbh i discovered that nvedit didnt work with me, through terminal,
didnt remember my
dev /cpus/PowerPC,G4@0 et cetera ...
i suppose because my lithium ion small round battery is dead
have to put a new in, so for me it meant no nvedit ... & no restore, & bootscript et cetera
just
every boot typing ( that's okay, at the end, you know what to type from memory)
dev /cpus/PowerPC,G4@0
80010201 encode-int " cpu-version" property
device-end
multi-boot fw
4) from then on just follow the instructions that automatically pop on yr screen
i.e. a) diskdrive mac os 9 app (by that time you are already in mac os 9 (restore) CD disk)
to partition your mac os 9 drive (it's called initialize in mac os 9 lingo )
b) restore through , i forgot the name of the app, image/software restore or something
the .img that is on the mac os 9 CD ...
F7 to go to the right screen ( 2 options for monitor)
5) very important: erase multiprocessing folder (also in trash recyclebin)
install jasper graphic driver (from darth vader)
erase or move all ati & nvidia acceleration & other graphical drivers
to the extensions-off or other map
If you don't do this , it can freeze
if it freezes, just press apple + shift + ESC to put acceleration OFF
++
https://mac-classic.com/articles/mac-os-9-on-unsupported-systems/i actually followed this, except for the multi-boot fw line after device-end
So yeah, now it boots from an exernal fw hdd partition, that probably i can just put in the internal atapi
or pata connector inside the powerbook ... next step will be probably finding a ssd sata to ide adapter