Good question. I've been through the same routine - warmed domains for weeks, kept an eye on reputation, thought I was golden. but the real gotcha is that warm-up is just the starting line, not a permanent pass.
For periodic checks, I'd suggest adding a couple of things alongside Snov.io's built-in monitoring and MXToolbox's free tier. i run my outbound domains through MxToolbox's full blacklist check weekly - the free version only shows a few blacklists, but the paid one covers the lot. also worth Google Postmaster Tools if you're sending Gmail-aligned mail. silent but gold for spotting delivery dips before they hit your inbox rate.
for a more hands-on approach, I'll fire off a test email to a throwaway Gmail account and check the raw headers for SPF/DKIM/DMARC pass/fail. Snov.io's reputation reports are okay, but they won't catch everything.
Upgrading MXToolbox? Depends on volume. if you're sending to more than, say, 10k contacts a month, yes - the blacklist monitoring alone saves headaches. Otherwise, stick with the free tier and supplement with manual header checks.
What tool are you using for domain reputation on LinkedIn sequences? that's the part I'm still scratching my head over - happy to swap notes.
