I feel like I'm stating the obvious, but you guys are laying out for indiegala what to take away.
Don't be surprised if the refresh gets patched now and costs you silver every time.
Or the few challenges left that are viable at high malus getting nerfed.
I'm not saying not to share your thoughts but maybe someplace more discreet.
I'm not too worried about that - all these things like high skill tactics or when exactly the game takes silver have been discussed repeatedly since the challenges started and nothing about that has been fundamentally changed.
Sure the difficulty was adjusted several times and the malus system was introduced to prevent skilled players from winning 24 times a day, but not all the changes were strictly about raising the difficulty. For example the sapling challenge used to be much less playable - it would almost never generate 40 light saplings and you often didn't have a chance of beating it even in 60 seconds. Or the grass mowing challenge, which didn't have single-hit tiles originally, so it was much harder to beat quickly.
Another example of a change that didn't make anything harder: several months ago I noticed that if you get all of the malus reductions available it would go to -1 and when tested it indeed meant that every time I won I would get extra time, that was fixed since then - nowadays you can only get malus down to 0, so our ability to win in that situation has been unchanged, but we don't have to spend more and more time on every challenge.
The way I see it, the gameplay giveaway's goal is too attract people to the site with the promise of freebies, so making those freebies impossible to get would be counter productive. The most important metric for deciding if they want us to able to win more or less must be the number wins we get and that data is always available to the devs, it's not something we can feasibly conceal. (At least without resorting to multi-account shenanigans and we don't cheat like that, right?) So in my opinion there's no need to be sneaky. Enjoy the challenges, enjoy your wins, if anything drastic happens, it would happen either way, after all nothing lasts forever, so let's have fun while we can.