Allow negative balance for an absence with two absence plans

We have Annual Leave absence which has two plans, Statutory & Non Statutory Plans. Both plans are incremental. When employee applies leave, Statutory plan has 1st priority followed by Non Statutory plan balance. System should allow employees to take leave beyond their accrued balance, up to the full annual entitlement.

Example: An employee with 2 years of service  is entitled to 13 days of annual leave (5 Statutory days and 8 Non‑Statutory days). By June, the employee would have accrued 6.5 days (2.5 Statutory days and 4 Non‑Statutory days). Despite this, the employee may still request the full 13 days (assuming no leave has been taken earlier in the year). This would result in a temporary negative balance of ‑6.5 days (‑2.5 Statutory days and ‑4 Non‑Statutory days), which will gradually adjust as accrual continues. The employee's balance for each plan should not go beyond the annual entitlement for the