speeding up the IDE-start through limiting the entries in preferences recent.sketches=

Today I looked up the preferences.txt-file to examine what additional switches are hidden in this file
Then I saw that the recent.sketches= -item had 70kB of entries!!

If I click on file - "open recent" the list shows ten files. Practical compromise between too much files and just three.

But why the heck does the IDE collect them all in the preference.txt-file?? Even if the 11 to 1000 entry are not accessible??
Can somebody give me a single reason why the Arduino-IDE can only work reliable with collecting all these entries?

That is what I call an old unvisible bug nobody wants to to clean up.
But this bug slows down the startup of the IDE. I guess if the line of code is found that causes this
adding the new file-entry and cut-away everything behind the tenth entry is done within 15 minutes or even less.

best regards Stefan

Inspect the Arduino IDE 1.x handling of preferences.txt, starting with the recent.sketches= entry, and reproduce the slow startup and Open Recent behavior. Trace where recent files are stored and determine whether the list can be limited to the ten entries shown; done means startup no longer carries the excess entries while the visible recent-file list still works.

Written by the indexing model from the issue text.