I've done it- moved completely off Spark. It wasn't that hard.
I was a power user of Spark for the last couple of years but this new update really broke my heart. I tried to stick with it but some of the changes were just absurd- the new iOS app makes my mailbox cluttered + that Sent with Spark signature in every email was disgusting. These were the features I was using every day and why Spark was my first choice-
- Using templates for mails
- Undo send
- Schedule send
- Sending mails via alias
- Custom swipes
- Snoozing emails
Turns out even basic mail apps like Apple's own Mail can be configured for all of these in 2022. No reason to stick around with this horrific new UI and cash grab. Abandon ship!