Have replied to this on your other post. Have you looked at the ‘vertical gardens’ use for pallets. Would make the front of your line blend in nicely. Details if how to vids on YouTube and plenty of other advice on Google.In summary it looks like you need the LGB units 10151 (or a diode bridge), for non-automatic operation. Fully automatic operation requires additional sensing systems to reverse the polarity of the controller at the opportune moment.
For the time being I'll continue with the straight end to end operation with a passing loop, the thinking is that changing points is an added attraction for the children, even if I find it a little tedious!