Keep the cowl screen clear. A common cause of under-dash water leaks and HVAC odors are from blocked drains and decomposing leaf debris.
I lay down newspaper or a floormat under the CAF when I pull it out. You can never be sure what is sitting on top of it. Sometimes they are spotless, sometimes they are loaded.
Maybe the battery disconnect is an over-abundance of caution, maybe not. The Stellantis legal dept has thought it necessary to include the warning. All auto manufacturers include this Airbag warning.
Some automakers state: 'See your dealer' when it comes to CAF service. Any DIY services not done by an authorized dealer is out of the manufacturers control.
In this highly litigieous society we live in, you can't be too careful or assume that people have common-sense or are mechanically-inclined. People get hurt, sometimes badly through no fault of their own. We want to avoid that.
Working on our pride & joy should be a fun and fulfilling experience.
Let's be careful out there.