Time Trial / Time Trialling / TT

I'm building some wheels that I intend for fixie skidding use and TTing. These aren't a TT only wheelset and I can't stretch to that. I originally planned to use H Plus Son Artchetype rims but am now considering something a bit deeper (SL42) to benefit my TTing.

Any opinions on whether the £23 increase in price and 290g increase in rotating mass are worth the aero advantage of increasing rim depth from 25mm to 42mm? Also of note, the archetype is a 23mm wide rim. The SL42 is 19.5mm wide.

Higher rotating mass is better for a TT unless it has a lot of bends you have to slow down for.