I had not noticed the Photos button. Thank you for pointing it out. I use so many different programs, some of which include a full array of editing features in their forums but many that do not. I've come to expect "not".
As for the history, my design does indeed have the entire history captured and listed along the bottom line. At no time did I " dispense with Capture of Design History". It might not have shown up on the photo I posted but that's because I cropped it in order to zero in on the issue I was concerned about.
As for timeline (and other) warnings: Little messages pop up in the lower right corner, with no sound to attract attention, and then within a second or two, fade away and are gone. They don't require an acknowledgement or clicking an OK button. They just vanish almost as quickly as they appear. That's not an effective way of assuring that such warning and errors are actually addressed.
Also, I've found that a lot of the warnings (and, yes, I get a LOT simply because I'm quite new at CAD design in general and Fusion 360 in particular) really don't do enough to explain what the problem is and in many cases provide NO suggestions as to how to resolve them. No doubt engineers who have years of experience with the tool encounter very few such warnings, since they've learned how to use most of it effectively, and have probably encountered the warnings in the past and learned from them. But for those just getting into the field, these warning and error dialogs are CRUCIAL to the learning experience. They MUST be absolutely clear, tell not only WHAT the problem is but WHY it's a problem and HOW to reasonably correct it. Critical terms on the dialogs should be clickable and pop up the meaning of the term. I have found most such messages on Fusion 360 to be lacking in one or more of those characteristics.
A simple example: I have another topic that I posted and the error message that I got was:
The projection of tool curve and faces fails.
UNDEFINED ERROR!
The UNDEFINED ERROR message is totally useless. The other message just tells me that Fusion "failed" to handle what I was trying to do. But what am I supposed to do with that info? I looked at a bunch of different possibilities and spent hours trying different approaches to resolve the problem. I finally found an approach that worked, but I still have no real understanding of what Fusion was having trouble with and WHY it was having such trouble.
So, my recommendation: Have your engineers and UI specialists spend a lot more time re-writing the warning and error messages so that they are informative and actually help the engineer to correct the issues. As they stand now (and especially since they merely disappear into the ozone a few seconds after appearing) they're more of an annoyance than a helpful feature.