The Junos 20 branch is now in Junos recommended versions for SRX1500 firewalls, see https://kb.juniper.net/InfoCenter/index?page=content&id=KB21476&smlogin=true
Upgrading those firewalls has several advantages:
- Testing routers redundancy in a planned window
- Keeping a tight Junos version spread (we currently have 12, 14, 15, 17, 18, 20)
- Fixing low risk security issues
As we're getting in the "no changes" time of the year, it will probably have to wait for next year. @Jgreen around what time should we ping you for that?