+1 for the adding the shadows and reflections to the assets.
I am not crazy about SA, but like your mod. Yes, other wood mods are available, but I much prefer your mod.
I started hacking it myself, moving the images to your assets but it got a bit deeper. So I figured I would ask here first.
No worries if you do not desire to add them, I can continue my hacking and resolve it for myself.

Hiya! For clarity, do you want the mod to be installable without SA enabled? I can certainly do that. I'll be keeping the feature tag enabled but I can duplicate the assets over to this mod so it's not dependent on SA

For myself, yes. I am interested in playing without SA, just 2.0.
I know these kinds of requests can cause headaches and refactoring, so no worries if this is not in your plans.
There is no need to alter your plans due to my personal likes and dislikes.

I made the changes for the images, sound, and explosions. But then tree-plant and agricultural-tower in base-data-updates.lua... I stopped there, figuring there is more to this than a couple of string changes, so I asked here.

Oh drat, yeah I didn't think about tree-seed and tree-plant. I may consider adding support for defining all the required prototypes if space age is missing, but yeah it'd be a considerable amount of work. Would you mind creating a fork of the repository on github and creating a PR with your current changes, and I can see what else needs doing? I wouldn't mind making space-age an optional module and including the necessary assets in the mod.

Sure, I can do that but I think wood universe assets is not yet public.

Oops, I just had the wrong link there: https://github.com/SafTheLamb/fm-wood-universe-assets

PRs submitted.

Thank you! I'll take a look shortly

I set this because I expect the recipe icon to be the product of the recipe, rather than a tree.

if mods["early-agriculture"] then
    data.raw["recipe"]["wood-processing"].icon = "__space-age__/graphics/icons/tree-seed.png"
end

I set this personal preference, but either way, probably an image to add to the assets.

I am no longer affected, I have decided to keep SA active. There is just too much to the downside. Feel free to revert the PR.