Love the mod, just wanted to offer a suggestion;

local custom_stack_size = settings.startup["asteroid-chunk-stack-size"].value

local list = {
"carbonic-asteroid-chunk",
"metallic-asteroid-chunk",
"promethium-asteroid-chunk",
"oxide-asteroid-chunk",
}

--if mods["suggested-mod-here"] then
-- table.insert(list, "scrap-asteroid-chunk")
--end

for _, item in pairs(list) do
if data.raw["item"][item] then
data.raw["item"][item].stack_size = custom_stack_size
end
end

and:

data:extend({
{
type = "int-setting",
name = "asteroid-chunk-stack-size",
setting_type = "startup",
default_value = 4,
minimum_value = 1,
maximum_value = 100
}
})

in a settings.lua.

You need a locale too, for mod-setting-name and mod-setting-description. Just a suggestion; mod is perfect without and has no need to be more complex. I just edited my own so I could test my own mods more easily :)