Has anyone found a wallet that allows multiple mnemonic recovery phrases to be inputted and view all balances at the same time?
Is your problem in the wallet or in tracking the balance of the wallet? If your problem is in tracking the balance or showing all your addresses in one place, there are many ways that enable you to do so using either the wallet address, master public key.
https://www.cointracker.io/wallet/bitcoinhttps://www.blockonomics.co/But if you want to collect all the seeds together, you risk losing all your money at once, always remember not to put all your eggs in one basket.
You can do this using password manager applications.