I bought a Ducky G2Pro Tactile mix board with Browns on the alphas, Clears on the mods. After using it a while I realised it was the wrong way around except for the spacebar since I press most of the mods, Enter, backspace, etc with my pinkies so they should actually be lighter. I always make my spacebar heavier than the others, for instance my board with ErgoClears has a stock Clear spacebar.
When I tested with heavier main switches and lighter mods it felt okay, but the stock Clears I used were too heavy and the small bumps on the Browns weren't quite tactile enough for nice feeling of actuation on the mods. So now I use all ErgoClears with stock Clear on spacebar as I mentioned before. I'd probably enjoy Browns on mods more with the lighter ErgoClears I have on the Alphas now, but there's not a big difference in force between them, so.... All the same feels fine if the switches are light enough.
Brown alphas with ErgoClear mods would also be nice, maybe the best combo since the extra tactility distinguishes the mod keys nicely by touch and they're light enough for pinkie actuation. Now that I think about it, just swapping the springs in the Clear mods (except space) would have transformed the board and made it feel really good.
For my ergo design board I use Browns on the main fingers, ErgoClears on the thumbs, arrows, edit keys, Esc and Del since I don't press them with my pinkies on that board and it's nice to have the added tactility on those keys to distinguish them.