How to separate words more clearly with spumux?

Hi,
First, thanks for these great programs!
I've been using spumux to add subtitles to a film.
It works well.
But it would be even better if words were separated more clearly.
More precisely, if the letters in each word were bound together, with no 
space (or almost no space) between them.
That would make the subtitles easier to read, each word forming a clear 
unit.
Is there a way to do that, by using a parameter, or creating a custom 
version of spumux?
Thanks,
David
(NB: Personnaly, I know very little about programming.)

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