Best Tools for Inbox Placement Testing and Blacklist Monitoring with 50 Domains and 100 Inboxes

Hey all, running Smartlead for sending and Zapmail for domains, 50 domains, 100 inboxes. What's actually working for you for inbox placement testing and blacklist monitoring at this scale? Looking at GlockApps and EmailGuard right now, curious what people are actually running day to day.