Hope you don't take this the wrong way, but I like that 55g scape better without the plants!
Not saying I don't like the plants, but there are some scapes that look better with only wood & rocks, and your 55 is one of them IMO.
It looks really clean and natural sans plants, and a little more staged with them.
Having said that I think the sight breaks are more important than aesthetics as far as the fish are concerned.
If I were you I'd wait to pull the other females until the male & a female pair off and aggression becomes and issue (if it becomes an issue).
I've recently pulled two GT's from my tank to medicate them and I've noticed that with fewer targets the remaining two females get chased considerably more by my male.
I am actually anxious to get the other female back in this tank but she unfortunately got beat up a bit by the subdominant male she is in QT with...
So in short what I am getting at is if you pull the other females prior to a spawn the male may actually get rougher on his prospective mate - especially if she isn't receptive.
I don't think GT's are renowned for abusing their mates like some fish are, but I am noticing my male is very persistent!