No known incompatible mods found yet, and no mod has been given explicit compatibility either.

If you find incompatible mods, please open a GitHub issue so they can be added here.

'How configurable each feature is' - the measure
☔ if on/off values,
☔☔ if editable lists/numerical values, 
and ☔☔☔ if on/off with editable lists/numerical values)

Or simply, more umbrellas more configuration potential

• Zombies can break blocks (☔☔☔)
• Additional zombie drops (☔☔☔)
• Entity multiplier (☔☔☔)
• Entity blocklist (☔☔)
• Daylight resistance (☔☔)
• Heavily armored zombies (☔)
• Day counter (☔)

this section is excessively verbose, read it only if you are confused with the config

The config file is present at your_minecraft_game_dir/config/zac-common.toml where your_minecraft_game_dir is your minecraft game directory.

REMEMBER!

only registry names can be used in lists, for the additionalZombieDrops list you can use registry names of items (minecraft:item) and for the entity lists you can use the entity's registry name (minecraft:entity) where item and entity correspond to the item/entity's registry name.

This should work with entities and items from other mods as well, but has not been yet tested.
You would simply replace the minecraft namespace (minecraft) with the mod's namespace (mod) and it would look like mod:item or mod:entity.

Here is a line-by-line explanation:

# integer (1, 2, 3...)
entityMultiplierRate = 1

Pretty self-explanatory

# list ["entry1", "entry2"]
entityMultiplierEntities = []

List of entities which are going to be multipled entityMultiplierRate times every time they spawn.

# list ["entry1", "entry2"]
entityBlocklistEntities = []

List of entities which either won't spawn or will instantly get despawned.

# list ["entry1", "entry2"]
daylightResistantEntities = ["minecraft:zombie"]

List of entities which will not burn in the day.

# list ["entry1", "entry2"]
additionalZombieDrops = ["minecraft:rotten_flesh=0.9", "minecraft:bone=0.1", "minecraft:carrot=0.009", "minecraft:potato=0.0009", "minecraft:iron_nugget=0.0005", "minecraft:gold_nugget=0.0001"]

List of additional zombie drops, the default zombie loottable is unchanged, these are merely extra drops with chances.

To get the percentage in decimals (as used here), just divide the percentage number by 100.

# bool (true/false)
heavilyArmoredZombiesEnabled = false

Does exactly what it says.

# bool (true/false)
dayCounterEnabled = true

Also does exactly what it says.

# bool (true/false)
zombiesBreakBlocks = true

Whether zombies should be able to break blocks in between its path to the player or not.

# integer (1, 2, 3...)
zombieBlockBreakReach = 3

How far zombies can be from a block and still be able to break it.

blockMinimumHardness = 0

Block hardness below which zombies cannot break blocks.

Check this out for more information about block hardness: minecraft.wiki

blockMaximumHardness = 3

Block hardness below which zombies can break blocks.