Are there any privacy benefits in using a separate wallet in Bitcoin Core to separate myself from my service?

Question

I currently run Bitcoin Core with the following wallets loaded in:

1. hot.dat. Contains the smallest possible sum of Bitcoin. Unencrypted and used by myself for various personal Bitcoin purchases, and I intend to have it double as the wallet for my Bitcoin-based website. (Unless you tell me a good reason not to.)
2. lukewarm.dat. Contains more than the "hot" wallet, but still not much compared to cold.dat. Encrypted with a long passphrase, but which is located on the same computer in a text document. I recon that it will stop at least automated malware which simply checks for wallet.dats and merely "sends them home". It of course won't stop somebody from manually finding the text document on my machine and figuring out that it's the passphrase to use.
3. cold.dat. Contains the vast majority of my satoshis. Encrypted with a long passphrase (partially stored on the same computer) with a bunch of additional parts with "hints" to myself rather than explicitly spelled out. This passphrase has never been entered to unlock the wallet outside of the dedicated Linux computer where it was created. (Not this machine.)

I'm aware that many would not consider my cold.dat to be a "cold wallet", but I thought the naming scheme fit well enough. The reason I don't use a truly "cold" wallet (where it's not stored on a "live" computer even encrypted) has to do with me fearing losing the file or having a fire or getting it seized more than I fear somebody first hacking into my machine and then somehow figuring out my complicated passphrase scheme. I consider that so unlikely that it is far more likely that I would lose access to it in other ways.

Now I wonder if I should be having a separate "service.dat" wallet dedicated to my new service, or if I can just generate new receive addresses for my existing hot.dat and use those. Is there any privacy benefit in me doing that? Or would I just be wasting yet another transaction fee to send over some satoshis from my hot.dat to my potential "service.dat"?

What if somebody who I do private business with knows who I am (because I have to give them my home address) and when I've paid them using hot.dat, those "inputs"/"outputs" are reused for my service, and suddenly they can associate me, the individual, with my service? And would that change at all if I used a separate "service.dat" wallet for the service? Won't it be the same "track" either way?

It's not something illegal or immoral. I'm simply trying to avoid any association between myself and the service, plus I'm also curious about this in general.

Answer 1

Yes, it's good practice to use different wallets for different mental entities that you don't want associated. Two different wallets cannot be linked from blockchain data alone.

However, that doesn't mean they couldn't be associated by different means, say someone seeing you use both of them, or monitoring transactions that are first relayed by your node.