For winter use, I have a somewhat unusual take but that might give you a product that's clearly distinct from competition:

I don't wear knickers or long tights with chamois built in; I almost always use chamois-less tights over regular shorts. (That lets me mix & match rather than having pricy gear that I only use a few months of the year.)

Lately I've been using the liners from MTB shorts which have thinner fabric so the combo is less bulky, but they rarely have very good chamois.

So my suggestion would be to make liner shorts with a very-high-quality chamois that go well under tights or paired with MTB "baggy" outer shorts. Great for epic MTB rides too!