What Bitcoins101 said isn't incorrect. You are basically saying the same thing but in different ways. A seed generated on a hot wallet always remains hot regardless of what you do with it afterwards. Its origins will never change. Bitcoins101 is also correct when he says that importing such a seed into a hardware wallet can potentially decrease your security. Each time you replicate your seed across multiple software, you increase the attack vector. You now have two pieces of software that hold your seed instead of just one. Open-source or not, you now have to trust two companies or groups of developers that they did a good job with securing their products so your seed doesn't leak and end up in someone else's hand. Import the same seed into a third software and this number increases to three, and so forth.