I didn't have time to make tests because in this days I worked at my leOS2 scheduler so I don't know if there's a method or a trick to do that.
I cannot help you, sorry.
Bear in mind that you can edit boards.txt and remove unused entries (it's the first thing I do with the boards.txt that comes with the Arduino IDE).
I know. It's the first thing that I do too. I cut all the entries not used like old boards or useless clocks, both from Arduino boards.txt and from Tiny boards.txt.
So, I have a lot of entries that goes over the bottom border of the screen. Is only me (Linux box) or someone else has the same problem?
I do.
Uhm... it's time to notify the problem... 