Good that you follow the technical progress. Your token can work with hardware wallets. For example, Trezor? I believe that hardware wallets are the safest.
Yes, I don't think there is an issue keeping ONEX on Trezor. I can not verify at the moment ONEX works on Trezor though because I don't own one. Trezor supports ERC233 and Ethereum Classic so it should be fine. Though you might have to access ONEX tokens using MyEtherWallet. Using MEW you would connect to ETC(GasTracker) - Connect to Trezor - wallet address.