So, I waited a year for the bugs to be shaken out of Cloudflare’s Email Routing before dipping my toe in the water. I have 3 personal domains with about 5-8 email (aliases) each. I wanted to send them to a personal Gmail account.
After configuring Cloudflare Email Routing I found that some (most??) email forwarded to the personal Gmail account but some did not. During the 2 weeks I trialled this, some business’s contacted me to say that emails to me were not succeeding. No logs showed on my Cloudflare dashboard to indicate anything amiss. I got no indication from Gmail. Nothing in spam folder.
I then switched to a dedicated email forwarding host (forwardemail.net in this case) and saw formerly unsuccessful emails immediately began arriving as expected in the personal Gmail account. (I now have SMTP as well, which is another topic).
My conclusion is Cloudflare Email Routing is a cool idea but not fit for purpose.