When is the Best Time to Start Sending Design/HTML Emails in Cold Outreach Campaigns?

Hi All! I'm a new GTM Engineer and I very obviously started w outbound cold email campaigns. I've been very curious about one thing - At what point of time can i actually start sending out design/html based email to a leads that i source? What i mean is that the natural sequence I know is leads get a "no link" cold email >>> after few touches >>> gets a design based-clickable email (which is basically a warm nurture email campaign). Asking this to understand the technicality behind the making getting the email to sit in the Primary Inbox. Am i even getting this right? Help me understand. Thank you The internet and gpts have been helpful to an extent, I truly want to know your perspective and guidance on how to approach this. I really appreciate any inputs! Also, PS: Can you pls point me to any slack channels officially run by Instantly?