It’s an interesting question. I see lots of uses for coloured coins etc, so I hope similar functionality will be possible on the safe network, but with the speed, capacity & security benefits of Safe.
This thread may also be interesting, as its about creating a public ledger on Safe, which I guess could be used for custom tokens: Public Ledgers and Proof of Transparency on SAFE
I don’t think there will be any way of querying the network to find out how many SafeCoin exist, or which ‘addresses’ own them, but someone with more detailed knowledge can expand upon why that’s the case, or correct me if I’m wrong.
If a distributed ledger is developed on top of Safe, then it’ll be visible how many of those tokens exist & where they reside, like with a blockchain.