Hey, first of all I wanted to say I love the mod and I'm so happy that someone takes the good both from Bedrock and Java and combines it to make an optimal experience!
The second thing is, this issue will be going over multiple suggestions that may or may not be programmed together on bedrock, If you'd prefer to handle some of the things here seperately, please tell me which seperate issues I should create and mark this one as Invalid.

So, in Bedrock, snow has physics (like Gravel, Sand and the Anvil). Instead of breaking into a snowball (or multiple snowballs) when the block below it is broken, it falls down to the block below, keeping it's snow value (the amount of layers). I'd love to see this feature in Java and I hope it wouldn't be too hard to implement.

The second thing is a mechanic called "Snowlogging". In bedrock, some specific blocks (mostly vegetation and flowers) are able to be "Snowlogged". I'd explain it myself but I think the Wiki does a way better job - https://minecraft.wiki/w/Snowlogging
I love this feature and I think it would be amazing to see in Java and bring variation to the layers, which brings me to the last suggestion, which is probably (at least in some capacity) related to this one.

In Java, by default, top snow generates exclusively in single layers. In bedrock top snow can generate in multiple layers, although I'm not sure if there are limits and such as to how far it . I'll run some testing if you want me to.
And now, post-generation. After the generation of the world, each snowfall can create snow layers on top of exiting blocks, On java snow can accumulate up to just 1 layer during snowfall (0-1), while bedrock can get up to 2 (0-2), creating some nice variation between layers.

Thank you so much for reading! ^^