ensure chip is of good known origin[msd,collins etc]
check basic engine is up to coping with the upgrade
make sure fuel pump is getting good power supply[nice fresh pump harness helps]-new quality fuel filter and good strong pump
set fuel pressure to chip providers spec[normally standard]
make sure plugs/leads/cap/sensors all a1[plus all connections]
make sure all hoses/clips pipework secure -particularly fpr/actuator related
set co to chip providers spec
set boost to level recommended by chip provider

would recommend not held at load for long untill afr/det checked on road or dyno

people wonder why a tune up /upgrade costs a few quid and they put in a car needing lots of work before any upgrades begin...

9 psi isnt a lot of boost on greens...most run 3x that it would seem
when i firs had cossies in late 80s/early 90s stage 3 was 21psi