more space for instrument names

[Stefan Thomas]

Dear Lilypond-Users,
I use very often the very nice \inst-Plugin:
changeInstrument =
#(define-music-function (parser location string) (string?)
        (make-music
                'TextScriptEvent
                'direction UP
                'text (markup #:bold (#:box string))))
       
inst = #changeInstrument
 Unfortunately, this does not work in conjunction with

\textLengthOn

What can I do to change this?