Hi @dhruvm,
Thanks for sharing this question with us.
Yes you can certainly custom code your template to optimize it for mobile. However, your custom solution may require additional assistance from a developer to ensure you have a mobile friendly view. If you do not have access to a developer, then please consider our robust community of partner agencies to assist with this. You can browse our Klaviyo Agency Directory to decide which option is best suited for you.
You can also use email preview services like Litmus or Email on Acid to see what your emails would look like on different platforms prior to sending
Additionally you may find the following guides helpful:
Troubleshooting Custom HTML, CSS & Javascript in Klaviyo emails
Optimizing emails for mobile
General templates doc
Thanks for being a member of our community.