I was thinking more along the lines of a printable report generated by a control panel, like this:
A control panel with 3 sections:
1. Choose topic (from a dropdown similar to the tag dropdown?), click button.
2. Choose format, click button.
3. Choose both a topic and a format. click button.
Option 1: a new tiddler is created.
Title: [Topic], organized by [format]
Text: List of tiddlers tagged with [Topic], sort [Format] display [Format] as heading, list or transclude tiddlers with [Topic] and [that format] under heading, display next [Format] as heading, list or transclude tiddlers tagged with [Topic] and [Second format] under heading, etc
Option 2: same as 1, but with topic and format inverted
Option 3:
Title: [Topic], [Format] (or something like this)
simple list of tiddlers tagged with that topic and that format.
Two examples of report for option 1:
Title: Birds, organized by formats
Text:
!!!Links
<transclude text of tiddler 1> = Link to National Audubon Society
<transclude text of tiddler 2> = Link to eBird.org
!!! Reflection questions
<transclude text of tiddler 3> = Why are birds so weird?
<transclude text of tiddler 4> = How can we monetize birds?
Title: Breakfast recipes, organized by main ingredient
Text:
!!!Eggs
* [[Ham and cheese omelette]]
* [[Eggs sunny side up]]
!!!Carbs
*[[Tamales]]
!!!Vegetables
*[[Huarache de nopal]]
Notes:
a) you can just dump an idea in a tiddler and tag with both kinds of tags. No organizing.
b) Later, you can automatically see your information, sorted.
c) Bonus points if the user can create their own [1] and [2] filters (instead of [Topic] and [Format], could be [Book topic] and [Book format], [Century] and [Location] (to orgz historical people and events), photos sorted by [Year] and [Location], etc.
d) Bonus points if th user can grow a list of choices for those filters (rather than have to add them at the beginning once, and then is locked in and can't add "Tamales" later)
e) Seems like all this is doable in TiddlyWiki. I know that tiddlers can be sorted in this way in a list filter, complicated though it may be, so there must be a way to filter/input by one or two criteria (tagged x and tagged y) and press a button to generate a pdf-able list for, example, sharing.