I am confused by the different interfaces I see on streams versus what I see on some websites. Some games have a max win of x1000 while others go up to x5000 or even higher. Are these all the same game with different skins, or are the math models actually different between developers like Spribe and BGaming?

The math models definitely change depending on the provider, which affects your potential payouts and the frequency of wins. For instance, the Plinko Casino Game versions from developers like BGaming, Spribe, and Turbo Games have different betting limits and max multipliers. You can find a useful link that compares the attributes of these providers, showing that some have a max win of x5000 while others might be capped lower but offer different volatility adjustments.