I know about those wallets i mean one that is dedicated to the testnet only the testnet.
I don't know your intentions but running testnet mode is only dedicated to testnet there's no interference from your standard wallet, coins from testnet can't be spend in real life but if you still insist on the testnet only wallet you can get the source code and eradicate what you don't need just it has been advised but you will need understanding on how the code works