\set Staff.timeSignatureFraction = 4/4

[blackstone . robert]

Dear all, 

Is it possible to undo or stop "\set Staff.timeSignatureFraction = 4/4” halfway 
a score? 

I’m presently transcribing, from a facsimile, an Aria of Sigismondo D'India 
with three sections: a first aria, a recitative and a second aria.     

The first aria and the recitative have \time 8/4 but the facsimile shows C 
(timesig c44)
at the beginning and therefore I added \set Staff.timeSignatureFraction = 4/4. 

The final aria however has \time 3/2 and in the facsimile it shows “3” in both 
staves so I  marked it as " \override Staff.TimeSignature.style = 
#'single-digit", adding \time 3/2.
That did not work because of "\set Staff.timeSignatureFraction = 4/4" at the 
beginning.
Hence my question.

Thanks in advance for any advice.
Best regards.

Robert Blackstone