I’ve done both and I think that I prefer separate. Either way it is a great combination but when separate them into separate baffles you reduce the bass vibration and resonance on the mid and upper frequencies of the F15. They sound slightly less murky in separate baffles.
Additionally, you can set the F15s to the sweet spot of your listening position and then move the low bass to align with the lower ranges of the F15 and find the sweet spot for the room’s low frequency response.
Finally, you have more ability to set the vertical position of the F15 at the optimal height, which I find to be a little too tall when placed above the W15 if you give enough baffle space to both drivers.
I definitely understand your desire to streamline and downsize. I find the F15s to be wonderful drivers on their own, and only gain a little extra oomph below 85 hz by adding the W15. Realistically the low response of both drivers is pretty similar so you don’t really gain much by reducing the low frequencies directed to the F15 and redirecting them to the W15 by using a crossover. You really are just bolstering the low frequency response of the F15 with the additional poor (lol) low bass response of the W15 by adding a second amp and driving the W15 with sub frequencies. That’s why I think these two drivers have so much synergy as opposed to other subs with the F15. YMMV.

Awesome looking baffles, by the way!

Yes, please keep me posted on your experience/results.

The subwoofer amp.

Very cool. Thanks for sharing your build, and I don’t see anything wrong with your staining. From the photos you have posted you definitely have your own style, and that’s cool.

I have used a bunch of different Dayton products over the years but not those amps. Any idea what frequency you are crossing over at? I’ve been at 90hz for a while now on mine.