Excellent! Puntuado con 5 de 5 estrellas

It works and it restartless!
But there is one thing, that I bеg you to add.
Firefox allows to open the bookmarks in sidebar too and in sidebar the positioning even more important then in the main window. Especially, horisontal positioning.
I saw, that your addon adds both dimensions - vertical and horizontal, they affect main window, but don't affect sidebar.
It would be really great, if you add this ability to sidebar opening.
The third parameter that is worth to add is zoom (in percents), especially for sidebar. Currently there is no possibility to change zoom in sidebar at all.

Esta valoración es de una versión anterior del complemento (V0.92.rev29.1-signed). 

position restore in sidebar pages

I investigated in your request. Currently I see no possibility to set a position or make selections on sidebar pages. It seems also not possible to do a manual search in sidebar.