I see now we can have multiple autotag timelines. Any possibility of having multiple tag timelines, too?

What I would like to achieve are independent tag sets: one set from a server which are fixed (or at least given), bound to one timeline: Accounting (project, subproject, etc)

A separate tag timeline that is freeform, allowing me to assign my own categories.

for just the reason stated. One set of tags who's values are retricted - can only bill to certain project/subtasks, for accounting purposes. I do not control these categories, they are forced upon me. All time (in principle) must be accounted for among those categories. Let's call these tags "Accounting".

I would like to collect more useful information, though, on another tag timeline - let's call these tags "Mine". They are sometimes refinements of the accounting categories, sometimes they are things that are completely apart from those. They involve repeated types of work for which I would like breakdown, like Documentation, Research, Requirements Gathering, Discussion, Design, Coding, Refactoring, Meetings, Testing, Admin, Support, Compliance, Training, et al.

These are the kinds of things that are common across many projects, and are useful to track, so I can show that where we spent more time on categories A, C, F, we spent much less time on Support, and had overall shorter timelines for subsequent work on a project.

Some of the above assignment (for either "Accounting" or "Mine") I accomplish via autotag, some must be done by hand (where there are significant "holes" not captured by a useful autotag. So, I must assign the autotagged time to a hard billing category, e.g. When that time has already been tagged by one of the tags from "Mine", though, it's not so clear where I must fill in the gap in the Accounting line. Usually I look to see if the Accounting categories total up to a day's time, but it would be better if it were just segregated, so the gaps would be apparent.

I currently double tag by hand. I start with Autotags that happen to find things by Accounting breakdown, which gives me some coverage. Then I go through by Document group, then by application group, manually. If there are still big gaps, I delve a little deeper, like looking at the details of the above.

Using coloring for finding gaps doesn't work so well, because I have assigned different colors to the various subtasks (Project1/Deployment from Project1/Development from Project2/Development). Plus, the colors are reused elsewhere (for autotags or other tags). I haven't been so diligent about assigning the colors themselves, beyond to see that they are different in certain cases.

I suppose what might help would be to be to show/select only activities which remain untagged by _certain_ tags (namely, some accounting tag) rather than just untagged in general. I can get a glimpse of the regions in question by filtering the tag timeline, but that filter does not remain in place when you switch to another timeline to use its entries.