Static unstability,
No - you have to meet the requirement for PC2; as far as performance is concerned, that is second segment climb (150ft/min at Vy at 1,000ft above the take-off surface) and PC1 en-route (50ft/min climb at MSA - which does permit 'drift down').
The take-off mass for PC1 is governed by the requirement to ensure that distances required (rejected take-off; and take-off distance) are within those available* plus, first segment climb (100ft/min at 200ft) and the other performance elements specified above for PC2.
Jim
*With the exception that the take-off distance available can be ignored if all obstacles are cleared vertically by 35ft.
155 man crossed with me; I would add to his statement that with the appropriate approvals, exposure can be taken up to 200ft (so no safe-forced-landing requirement).