There's always bookmarks you can use, also groups (groups within groups), and comments. I find different too many event sheets per layout hard to work with, So I mainly use one per layout then open or close groups instead depending on what layout.
Usually i have all controls related stuff in one group, UI stuff in one group, Other logic/game events and stuff in other groups, And then using subgroups for specific things. By deactivating unused groups you can save a lot of processing power as well. The less events the engine has to go through each tick the better.
Another good way I find really useful for organizing is using functions. Instead of having a HUGE list of sub- events, conditions and actions and I call functions instead. Functions you can name properly, and find more easily for specific things.
On mousebutton down:
---> Call function: CharShoot
---> Call function: CharSound
---> Call function: UpdateBullets
---> Call function: CharAnimation