Is there a requirement to use the eosio.token account/contract for managing tokens?

I understand that the eosio.token account/contract is used to maintain a ‘register’ of tokens and also maintains a balance for each user.

Alternatively, I could create my own account and implement the eosio.token contract to that account. I could take the opportunity to modify the eosio.token code to store additional information on each user (e.g. account type, registration date, etc).

If I take the latter approach I can effectively maintain my own version of a token ledger, however I suspect I will lose some functionality. For example, what if an exchange or another user (outside of my system) wants to credit one of my users with an amount of my token?

My question is: should I use the eosio.token account/contract to manage create/issue/transfer of my system’s tokens – or should I create my own version?

[I suspect that I will have to use the eosio.token account/contract as that is publicly available, and build any extensions, (e.g. user registration date, account type, etc) in my own multi_index_table]

void token::create( const name& issuer, const asset& maximum_supply )
{
    require_auth( get_self() );
    ... 
}