You have limited options for a good, open source multi-currency wallet, and those options may be limited to Unstoppable wallet which may have sync issues or slow sync.

The best thing is to be wise in your investments and try to reduce altcoin investment, because you do not diversify your investments, but rather increase the risk potential while reducing the return on investment. In this case, hardware wallets give a safe and easy-to-manage option instead of software wallets.

Find a suitable option here https://wallets.thebitcoinhole.com/ and ask the community if it is suitable for you.