It is straightforward that if one does not attach PCC for countries where they've stayed for more than 6 months at a stretch within last 10 years, application will be rejected. But, what about the following cases (all are applicable for me)
1. Stayed in a country for more than 6 months at a stretch, but before 10 year cut-off period - Australia
PCC is not required in this case...
2. Stayed in a country for 4.5 months at a stretch within 10 years, but stayed for more than 6 months at a stretch before 10 year cut-off period - US
Although PCC is not required in this case, but getting a FBI PCC comes in handy for faster processing...
3. Stayed in a country for more than 1 year overall within 10 years, but never more than 1 month at a stretch - Kuwait - here added issue is that I was always traveling on business visa, so cannot apply for a PCC as I did not hold a residence permit
PCC is not required in this case... You can explain in LoE the KW only issues PCC to current or former residents only.