New Crossover for S8R Olympus

Hey all, Iím after some advice on upgrading the crossovers on my JBL S8R Olympus speakers. The current crossovers are LX5 and N7000, but it donít want to recap and they are sealed and Iíd rather keep them as they are. Iíve read the below thread and one of the respondents propose a new single crossover to replace the two (see attachment)proposed x-over for S8R.pdf

I have a couple of questions. Firstly does this make sense, and secondly Iím unable to find 13.5 uF caps, would 13uF do?