We updated from RH5 to RH8. In RH5 the writer created three separate projects and chms rather than use condition tags.There are probably 30 unique topics per project.
We want to combine them into one project with three condition tags. It seems like the simplest way is to do it manually: Open Project A topic A1, then open the html topics B1 & C1, copy the differences into topic A1, and set the diffs as conditional text.
We have many legacy projects. Is there a better way? Perhaps import the unique topics and use an RH8 compare tool of some kind, or use an external editor such as Ultra Compare?
You seem to have considered all your choices already. Three things, though: