My dude, I think it's done!
Finally found a way around it, without any of the bugs, like tier 7, or going back to level one once pass the required magazine level.
Here is an example from the edited progression file:
Vanilla
<passive_effect name="CraftingTier" operation="base_add" level="3,5,7,10,100" value="1,2,3,4,4" tags="meleeToolRepairT0StoneAxe,meleeToolShovelT0StoneShovel"/>
<passive_effect name="CraftingTier" operation="base_add" level="14,18,22,26,100" value="1,2,3,4,4" tags="meleeToolPickT1IronPickaxe,meleeToolShovelT1IronShovel,meleeToolAxeT1IronFireaxe"/>
<passive_effect name="CraftingTier" operation="base_add" level="35,43,51,59,100" value="1,2,3,4,4" tags="meleeToolPickT2SteelPickaxe,meleeToolShovelT2SteelShovel,meleeToolAxeT2SteelAxe"/>
<passive_effect name="CraftingTier" operation="base_add" level="70,80,90,100" value="1,2,3,4" tags="meleeToolPickT3Auger,meleeToolAxeT3Chainsaw"/>
Edited
<passive_effect name="CraftingTier" operation="base_add" level="3,5,7,10,13,100" value="1,2,3,4,5,5" tags="meleeToolRepairT0StoneAxe,meleeToolShovelT0StoneShovel"/>
<passive_effect name="CraftingTier" operation="base_add" level="14,18,22,26,30,100" value="1,2,3,4,5,5" tags="meleeToolPickT1IronPickaxe,meleeToolShovelT1IronShovel,meleeToolAxeT1IronFireaxe"/>
<passive_effect name="CraftingTier" operation="base_add" level="35,43,51,59,67,100" value="1,2,3,4,5,5" tags="meleeToolPickT2SteelPickaxe,meleeToolShovelT2SteelShovel,meleeToolAxeT2SteelAxe"/>
<passive_effect name="CraftingTier" operation="base_add" level="60,70,80,90,100" value="1,2,3,4,5" tags="meleeToolPickT3Auger,meleeToolAxeT3Chainsaw"/>
I basically added a double "level 5" so that when it reached max level, it's still tier 6, and also added an extra trigger level to each tool type. In some cases the last level of one tool overlap with the first, or first couple, or the next tool, but I don't see that much of a problem.
If it bothers though, it can still be fixed by adjusting how many magazines are needed between each trigger, so that they all fit neatly in the limit amount, which is from 50 to 100, depending on the category.
I hope any of this is clear, as it kinda confused myself as well. I'd use the excuse "English is not my first language", but truth is, I wouldn't be any better in my main language either, explaining this kind of stuff XD .