To upgrade CISCO ISR 4321 router IOS version from 16.6.4 to version 16.9.5, does it need to upgrade ROMMON version of router as well?Current ROMMON version is 16.7(3r)

Any solution for below error?#sh ver | i IOSCisco IOS XE Software, Version 16.09.04Cisco IOS Software [Fuji], Catalyst L3 Switch Software (CAT9K_IOSXE), Version 16.9.4, RELEASE SOFTWARE (fc2)Cisco IOS-XE software, Copyright (c) 2005-2019 by cisco Sys...

I want to set both new and old IOS image in boot path variable on CISCO catalyst 2960/3750/9300/3850 series switches.If i set boot path as below it can work or not?Just have doubt about if new image code broke during upgradation then switch automatic...