If you think it is that necessary, start drafting the BIP, or switch to a coin that has your desired 11 decimal places (wtf?) to begin with.
Your apparently perma-state of amazingness prevents you from reading correctly. I proposed 10K million UNITS. Not decimal places. If you want to Wow-Such-Amaze yourself even more, realize that im proposing here :
10,000,000,000.00000000 Omg. Very numbers. much headache.
You need to understand that
in the protocol the unit is the satoshi and the value is just the number of those. Having 8 decimal places in Bitcoin is just the wallet's way of displaying that; it's not doing floating point maths in the protocol. As a consequence it really doesn't matter where you put the decimal point as these are just abstract numbers.
So the maximum possible number of units for Bitcoin is 2,100,000,000,000,000, and you are proposing an altcoin with a maximum of 1,000,000,000,000,000,000 - only around 476 times more.
Hopefully you can see that
if the supply limit is a problem then a coin with a supply 476 times higher probably isn't going to be enough. Also I hope you can see that it's rather pointless worrying about this non-issue now when it would be a lot more productive to see at what level usage settles at and soft fork if necessary.
You must admit that if you created an altcoin right now with the properties you describe, it would almost certainly be a flop as it would get no traction compared to bitcoin, which probably explains why the only people seriously discussing this are the ones who don't understand and are inventing work for hypothetical other people to carry out.