Azure Application Gateway Downtime

[N V]

Hello,

Will there be any downtime if i update Azure Application Gateway (for eg, disabling a few rules on the gateway) . We have configured 2 instances of Azure Application Gateway

[#2]

Modifying you gateway will only result in downtime if you make a change that doesnt work, so i would always make sure to have this in a planned service time frame. 

are you using two gateways for the same application ? if so you could just use 1 gateway resource with multiple instances, this is also required to have the 99.95% SLA

[#3]

changing the rule or removing one unhealthy backend pool should not cause downtime in production. Customers are complaining about this downtime behavior as for production website small changes cause downtime. Is there any plan to fix it or improve .