Best way to handle event signups (paper list) + flows + double opt-in?

Hi everyone! I’d love some guidance on best practices for managing event signups in Klaviyo.

Here’s my current setup:

• I have a signup form for a giveaway that uses double opt-in
• That feeds into an “Event Signups — Confirm Subscription” list
• I created a flow triggered by “Added to list” for that event list:
  • Email #1 immediately
  • Email #2 after 1 day
  • Then I add them to my main “Newsletter” list
• My Welcome Series is triggered by being added to the Newsletter list

Where I’m getting stuck is with paper signups from in-person events.

What I’d ideally like:

• Upload those contacts
• Have them go through the same Event Signup flow
• Then flow into my Welcome Series

What I’m seeing:

• When I import contacts into the Event list, they don’t always trigger the flow automatically
• I can manually add profiles to the flow, but I’m not sure if that’s best practice

My questions:

1. What is the best way to handle in-person (paper) signups in Klaviyo? (I’ve tried QR codes and I always have better luck with paper and pen sign ups. People tend to do it while they wait in my lines!
2. Should I be skipping double opt-in for these contacts, or is there a recommended way to still include it?
3. Is manually adding profiles to a flow after import normal, or is there a better setup I should be using?
4. Would it be cleaner to use a separate list or segment for event signups instead?

For context: these are people who explicitly signed up at markets/events to receive emails.

Appreciate any guidance — I want to make sure I’m doing this the right way as I grow 🙏