So Memo cash and Memo SV are different networks? If yes, is there an app for Memo SV? And finally why don't you merge them together in one app?
Yes they are different, once the unsplit coins run out, all messages will be different. Now some of them are broadcast on both chains , because unsplit coins are used.
Memo identify a message by its transaction ID. If a message have same transaction ID on both BCH & BSV chains, these 2 messages can be considered same, which requires unsplitted coins.
unsplit coins run never out.
There will be gradually less and less unsplit coins. This video illustrates why:
Yes, there will be less and less, but never run out to zero.
