Can I start with a disposable email and switch later?
It’s safe only if the site lets you change your email and you verify the new address before the disposable one expires. If you already know you’ll use the account long term, choosing a stable address from the start reduces risk.
Aliases and plus addressing are not the same
Many email providers support the name+tag format, but it still exposes the structure of your primary address, and websites may strip the tag. A separate alias has a different public prefix and can be paused independently.
The rule of thumb
Use a short-lived address for short tasks, a revocable entry point for ongoing relationships, and a stable email for important identities. Following this rule is more effective than cleaning up after marketing messages take over your inbox.