ProtonMail and SimpleLogin with Custom Domain Question

With ProtonMail now with SimpleLogin, is there any reason to not just add a custom TLD to SimpleLogin with forwarding to Proton?

What are the best practices when doing this?

I was thinking something like:

1. finances/real people get an alias from the custom TLD pointing back to Proton. Catchall turned off.
2. Services I use regularly get a subdomain alias from SL pointing back to Proton.
3. everything else gets a random alias from SL

Seems like a lot …

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