I'm slowly learning with my 790 Moses on a Fanatic Blast 115. Seems balanced. One problem I have is that the two areas I can foil most often have lots of chop or waves. One spot gets waves and swell in only 15 knots and the other spot is a lot windier with associated chop. Uphauling on my 65cm wide board is totally doable but I spend so much time falling in and uphauling at every transition/turn, it's exhausting. I figure I'd learn twice as fast if I had a wide stable board for better balance when not moving/transitioning. And if I do drop the sail I could quickly get it up again, instead of precariously balancing while slowly lifting the sail up. Of course with waterstarting this isn't an issue but i can't rig too big in gusty winds so I'm often underpowered for waterstarting.
Anyways, I might start looking at boards for next year, especially if I see something used. It looks to me that the most common shape for my size of wing is 120 to 240 L, with widths of 78 to 89 cm. What are the disadvantages to the larger board (I'm about 65 kg)? I've seen people mention swing weight but I'm not doing a bunch of swing tbh. I'd be happy with reaching with some gentle turns and a nice stable platform to learn to jibe.

Maybe I'll be past some beginners bumps by the time I see a deal on a foil board. My dream would be a week of 18kn side shore flat water with sandy launch. Sadly I get gusty 20kn onshore chop with rocky/boulder launch. Lots of people learn here, so really it's me but it feels good to vent sometimes.