Hi,
1,0 bar is realy no problem, with your intercooler 1,2 bar should be also reliable. Stock is 0,8 bar, so if you only have 0,5 bar, you are under stock boost level. If you wand to run with more than 1,0 bar, and get mor hp from the higher boost level, you also need a custom boost pin for you fuel pump, or live with very high amount of smoke, because otherwise you have to adjuste idle fuel amount to big, to get enough fuel at maxium boost.
best regards
Clemens