Hello,
my p3a battery is becoming affected by a concerning cell deviation, i've tried to deep discharge gently 'till 8% and full recharge it to check if this can improve the situation but 1st cell voltage still is not aligned with other 3 values.
Is there a way to balance it? I must buy some professional charger?
I'm wondering if Intelligent Flight battery electronics is designed to address this issue in some way or if it is planned in a future firmware...

The DJI intelligent battery has the charging circuitry built into it. It will perform fast charge and then balancing charge automatically. There is no point in trying to connect a different charger to the battery because it will not work.

It may be that you have a faulty cell in the battery, but the only thing you can do is discharge the battery and recharge it over several cycles. If that does not work, then you may have a problem. However, if the cell gets out of range too far, the DJI Go App will warn you about this, so until you get that warning, you could keep using it. If you do get a 'Damaged Cell' warning, then I would not use that battery again.