Legs require a bit of clipping. 1st image is with 0.5m added on the legs, second image is how the bluprint goes down.

You can add 0.5m signs directly on the end of the legs and copy and paste settings from the other 0.5m signs

I personally prefer 2m signs, but those can be a bit tricky to place. If that's something you would like but don't want to figure it all out yourself, you can look for the park bench RTC blueprint I have published! (https://satisfactory-calculator.com/en/blueprints/index/details/id/7603/name/Park+bench+RTC)