No, I came from an age where DIYers used an adjustable capacitor bank to dial in XOs and don't have any of my calculators loaded to make a reasonable guess for a good starting point.

Haven't tried it, but a lot of folks have been using this [now] well proven freeware with excellent results for getting a good-great starting point, though max accuracy [for the anal retentive] requires inputting actual driver measurements: xsim crossover - Google Search

Note that compression horns have a more complex impedance than a typical cone/dome driver, so what may look 'pretty' on paper usually will require some component value adjustment, often including any series resistance, so playing with a trim pot in place of R1 may prove beneficial for dialing in best overall sounding cap, R1 value combinations.

GM