As for replay protection, when someone makes a contentious hard fork, they don't bother implementing it, because they want everyone follow only their chain. But when someone creates a forked altcoin, they do want to implement it, because it would make it easier for their users.
I know they should have implemented, but they didn't. BSV developers didn't want to implement it.
This is why you have to split your coins first, as suggested in the guide I mentioned.
You can read about it here.
About replay protection:There is no replay protection between the BCH (ABC) and the BSV chains. This means that, unless you properly "split" your coins, transactions you make with one of those coins will also be made on the other.
Sending unsplit BCH will result in the same amount of BSV being sent to the same address (and vice-versa). The receiving wallet may not be prepared to accept BSV into their address, so there is a possibility of loss of BSV coins. This is not an issue specific to Coinomi, as any other wallet you use is under the same risk.
How to split coins:Splitting is only necessary if you had a positive BCH balance on November 15th 2018. If you received either BCH or BSV after that date, they are most likely already split.
1 - Receive a new deposit into your BCH wallet of BCH that is already split. Any value will work, however small. The easiest way is to receive BCH from an exchange. If you are sweeping unsplit BCH/BSV from a paper wallet, you must still receive split BCH from somewhere else before moving to step 2.
2 - After transaction from (1) is confirmed, open the BCH wallet and copy your current BCH "receive" address
3 - On that same BCH wallet, go to the "send" section and send your full BCH balance to the address copied above.
4 - Done. This should be enough for your coins to be split. This process only has to be done once. After your coins are split, they are split forever, and further deposits you receive will also most likely already be split.
https://coinomi.freshdesk.com/support/solutions/articles/29000026274-bch-abc-bsv-fork-information-splittingCoinomi is not as safe as a Desktop Wallet or a Hardware wallet, but it is extremely convenient as it supports both BSV, BCH and BTG. You can claim all of them easily, and after claminig them you can just move those coins to another wallet, safer. Or even sell them and buy some btc back.
Wow. Thanks for posting that. I didn't know that about the BCH/BSV fork.