I haven't looked at the Plykea stuff in detail but clear seals on everything seems to be the standard these days even for "natural" looking finishes. For large

I haven't looked at the Plykea stuff in detail but clear seals on everything seems to be the standard these days even for "natural" looking finishes. For large enough cabinet doors where you want a flat, flush, uniform look, plywood gives you dimensional stability which is a big deal. Also seems to be common. I'd band the edges in most cases though vs painting or such. Especially if you're DIYing, cause depending on just what level of fit and finish you want, you're gonna have a hard time getting things perfectly square, perfectly flush with most wood you'll be able to buy, without getting into jointers and planers and other fun stuff. It's easy to do "pretty good" and very very hard to do "very good" without either a significant investment in tools or time or both.