PokerTracker

Maybe this was already mentioned... but there should be a "Save and apply to all of my open huds of the same profile so I don't have to Reset every table to see this in effect, this will also prevent me from making unsynchronised saves at different tables" -option next to "Save" and "Reset" in the PT icon. Feel free to find a more catchy name, though ;)

Just save layout and restart hud imo

I'd rather not kill the hud on all of my tables, some of which might use a different hud, just to apply the changes globally.

In PT4, it actually does that. It will save and restart layout on all other tables where it's used. It's just not described in the command, and lags like hell so you didn't notice it.

also, a little long-winded:

make HUD changes
save HUD changes

open HUD configuration dialogue
select the HUD you've just made changes to
click Apply

changes will pull through globally.

whilst not what you requested it is a useful workaround when first designing HUDs AND still playing; however, you could just as well restart globally but you would miss out on the HUD info on one or two table actions.