Suppose I want my captions to start with -1 rather 1. Or to start with 20 rather than 1 since I'm writing a second part of a document. The "Insert Caption" dialog doesn't let me do that. Now, I realize this is a problem, because my choice affects other captions; but that is bug 153248, i.e. we already have that problem anyway.
There is at least a workaround, if you modify existing caption with Edit -> Fields. But I can't see a reason why value option shouldn't be part of insert caption and also auto caption dialog. cc: Design-Team
Wouldn't call the edit field workflow a workaround. And if you combine two documents the field numbers will be updated anyway.
We discussed the topic in the design meeting. The primary workflow is to insert a caption as quick and esay as possible. If we tweak the variable calculation it may has adverse effects for master documents. And experts can do the trick with a macro. So the decision is to not implement the idea.