What is the maximum signature ability level on Marvel Contest of the Champions?

When a player gets a duplicate of a champion he unlocks the signature ability. Each duplicate will increase the level of that ability. I have a Punisher with signature ability level 8.

How many duplicates of a champion can one get? What is the maximum signature ability level on Marvel Contest of the Champions?

I am not concerned by hacks and stuff... My question concerns the official game.

The maximum level for a Signature Ability is currently 99.

• Tier 1 champions have no signature ability.
• Getting a Tier 2 duplicate will upgrade a Signature Ability by 1 level. Exceptions: dupping Unstoppable Colossus and Punisher will increase their signature ability by 2 levels. I guess it is because they can only be obtained by alliance crystal and versus crystal respectively.
• Getting a Tier 3 duplicate will upgrade a Signature Ability by 8 levels.
• Getting a Tier 4 duplicate will upgrade a Signature Ability by 20 levels.
• Getting a Tier 5 duplicate will upgrade a Signature Ability by TODO levels.

It can be seen on this video, this reddit post and this Wikia page.