Any AMT / ribbon waveguide center speaker designs?

I’m hoping to build a center speaker with very limited vertical HF dispersion. My system is in a family room with wooden floors and minimal soft furnishings, and the center speaker will most likely end up sat on a low table under my wall-mounted TV (approx 300mm of table surface in front of the current speaker baffle). All in all, I know this isn’t an ideal setup, but I’d like to try something with very limited vertical dispersion to minimise the impact of table surface reflections (and also reflections from the wider room).

I’ve been looking at ribbon & AMT drivers with waveguides. I’d love to buy a Beyma TPL-150H, but the Dayton PHT1-6 seems pretty attractive for not much money.....

Due to limited vertical space a horizontal MTM is probably the only viable option. To minimise horizontal lobing I’d ideally keep the tweeter crossover frequency low, but with a ribbon / AMT / planar tweeter that’s not so easy....

I’ve searched for existing tried and tested MTM designs with these types of HF drivers, but found very little. Does anyone know of any DIY projects or kits I could read about? Many thanks in advance, and Merry Christmas!