There is a problem I am having with crafting certain items by hand. Green Science Packs, Fast Belts, Splitters, Underground Belts, Science Labs, etc. all use your 8 second long belt recipe.
Why is this a thing? I don't know any reason why this mod uses recipes, it only affects the map. Please remove the recipes or try to hide them from the game better.
The recipes I think are causing it:
zadv-express-transport-belt-slow
zadv-fast-transport-belt-slow
zadv-transport-belt-slow

Can confirm, happens when an item has to craft other products first, such as trying to hand craft splitters with no belts but plenty of iron plates on hand.

I think what will fix it is removing this chunk of code from data-updates.lua:

recipe = table.deepcopy(ZADV.backup['recipe-transport-belt'])
recipe.name = "zadv-transport-belt-slow"
recipe.enabled = true
recipe.hidden = true
recipe.flags = {'hidden'}
recipe.energy_required = 8
recipe.hidden_from_flow_stats = true
recipe.normal = nil
recipe.expensive = nil
recipe.ingredients = {
{"iron-plate", 1},
{"iron-gear-wheel", 1}
}
recipe.result = "transport-belt"
data:extend({recipe})

recipe = table.deepcopy(ZADV.backup['recipe-fast-transport-belt'])
recipe.name = "zadv-fast-transport-belt-slow"
recipe.enabled = true
recipe.hidden = true
recipe.flags = {'hidden'}
recipe.energy_required = 12
recipe.hidden_from_flow_stats = true
recipe.normal = nil
recipe.expensive = nil
recipe.ingredients = {
    {"iron-gear-wheel", 2},
    {"transport-belt", 1}
}
recipe.result = "fast-transport-belt"
data:extend({recipe})

data:extend({ZADV.backup['lubricant']})
data:extend({ZADV.backup['recipe-lubricant']})
recipe = table.deepcopy(ZADV.backup['recipe-express-transport-belt'])
recipe.name = "zadv-express-transport-belt-slow"
recipe.enabled = true
recipe.hidden = true
recipe.flags = {'hidden'}
recipe.energy_required = 19
recipe.hidden_from_flow_stats = true
recipe.normal = nil
recipe.expensive = nil
recipe.ingredients = {
    {"iron-gear-wheel", 5},
    {"fast-transport-belt", 1},
    {type="fluid", name="lubricant", amount=20}
}
recipe.result = "express-transport-belt"

data:extend({recipe})

Just out of curiosity, what is that code even being used for?

No idea.

I've made a Pull Request on GitHub for the recipes to be removed, please merge it if they don't do anything.

RU (Google Translate :D)
Я сделал запрос на GitHub, чтобы удалить рецепты, пожалуйста, объедините его, если они ничего не делают.

Should be fixed in 2.17.1