>> Transferring their fund by importing the 12 words into other wallets like Electrum might be a good step or any wallets that support importing BIP39 seed phrases.
That's not a good move. Importing 12 kata into the new wallet you want to transfer will be meaningless because the 12 kata you import are from the initial wallet you are using.The good thing is to send coins from the wallet you are using to the new wallet you are going to use.
But they use something "nonstandard derivation" for non-BTC coins and I haven't been able to import the seed into other wallets (Exodus, Trust wallet). I had quite a bit of USDT-TRX on it, as a hedge against Bitcoin volatility in my retirement years 
Unstoppable wallet that I can say is a good wallet for you to transfer existing coins in Trust Wallet and Exodus by sending them to the Unstoppable wallet that you created recently.What I say is the same as what has been explained by hosseinimr93