Unrelated to the functions as in not used, yes, but equal in strength is equal in strength. Again, I'm not talking decryption of public->private keys being a be-all solution to cracking wallets, but the level of strength is near or at the same levels, regardless of the protocols used. If you want to talk about ECDSA and cracking chains, let's talk hardwallets, going back to the original topic at hand.
You are completely misreading what OP asked about. What OP asked was:
So, is there any added risk when one hardware wallet is used to access multiple different cryptocurrency wallets? For instance, is it possible that the Ethereum blockchain data could at some point be broken to obtain private keys/seeds and using this information also access the Bitcoin wallet, or vice versa?
He asked if there was any
added risk with using the same hardware wallet on multiple coins. What you are talking about is risk that already exists with hardware wallets, BIP 39, ECDSA, etc. The only added risk comes from the blockchains used by the various coins, and the blockchain has nothing to do with your keys.
Sorry, this is what I get for browsing bitcointalk right before bed. Oh well, hopefully someone gets a laugh out of it, or at least a chuckle.