Having Blockus installed does not allow other mods to use shovels to create paths in the world.
Mods tested (and the paths they can create with shovels):
FabricAPI 0.24.0 build 411
Blockus 1.6.4 (Dirt, Podzol, Coarse Dirt-> Dirt Path)
MorePaths 0.0.3 (Mycelium -> Myc. Path; Podzol -> Pod. Path; Crimson Nylium -> Crimson Path; Warped Nylium -> Warped Path)
With Blockus installed, right-clicking Mycelium or Nylium will not produce a path. Right clicking Podzol or Dirt will produce Blockus' Dirt Path. Without Blocks, those blocks produce their usual paths.
I do not mean to be pedantic, but it is possible for different mods to add multiple "recipes" to a shovel (e.g. More Paths and MounderTweaks), as long as they do not try to modify the same origin block.

Also, this is more of a suggestion, but could the Dirt Path please be restricted to the "Dirts" blocks only? Or perhaps solely Dirt?