Narrow space between italic f and T with fourier font

consider the following MWE:

documentclass[%
11pt,
]{scrbook}


usepackage[widespace]{fourier}
begin{document}
of Theorem
emph{
of Theorem. 
}
end{document}

The space between f and T is very narrow with fourier font even when passing the widespace option (seems not to have any effect, though).

Is there a way to fix this without changing the font?

EDIT:
I realised, that the problem came up in a situation, where there is less whitespace for all words, see the following example

documentclass[%
paper=17cm:24cm,
DIV=12,
11pt,
]{scrbook}


usepackage{fourier}
begin{document}
emph{
    quadqquadqquad of Theorem\
assumptions of Theorem 2.6 hold. Further, let $cinmathbb R$  be given such that $1 < c < lambda/sigma$. Choose
}
end{document}

See the second example in:

documentclass[%
11pt,
]{scrbook}


DeclareRobustCommand{SetFourierSpace}{%
fontdimen2font=1.6fontdimen2font} %adapt the 1.6 default with widespace is 1.23
usepackage{fourier}

begin{document}
of Theorem 
end{document}