Hi!
This suggestion ("request" sounds a bit hard here) has my full support.
I am somewhat of an in and out player, so I can't contribute to the community as much as the hardcore players (no magma experience, no HFS experience, no successful aquifer handling, no glacier experience, no evil area fortress experience, ...). So, one way I try to contribute is by genning pre-generated worlds for people to use.
In order to maximize value of these worlds, I always have history on them hidden and actually upload them in the state before they are played even once (even without checking legend mode before making the backup).
I am now dabbling into playing fortresses to upload and share for other players to explore using their adventurers, and I find that the history is something of a bother. First of all, fortress history is revealed as far as I know, taking a lot out of the excitement of exploring the abandoned ruins. Secondly, since I enjoy fortress mode a lot myself, I have engraving history revealed for fortress mode - meaning that my fortresses are likely to tear holes into the shadow of history as well.
Thus, it would be great if I could simply reset the legend mode before uploading a world so that anyone downloading the world can discover all of its history and sites at their own pace and as their own achievement.
In this context, I would also like to re-iterate my suggestion of making legend modes with hidden events really completely blank so that it represents much more precisely how much the player has found out. After all, currently, the player can not really have the feeling that they have discovered the site of major historic battle since such sites and the details of the battle are already revealed before the player starts playing for the first time.
Anyhow, this suggestion has my strong support.
Deathworks