Are you sure on that? The interrupts are meant to be edge triggers from short pulses on INT0 and INT1. If a pulse comes and goes while EA is 0, won't it be ignored
The only thing you can lose when an interrupt is disabled by EA, ET0 or a higher priority running is you will only see one if two interrupts happen which disabled.

Anyhow what you are doing will fail since you have no "handle oscillations across the border" routine.

Erik