I will try keeping it short.
Kuva weapons are speacial, they can go to rank 40 with 5 forma. 5 forma per weapon is expensive(it has been said many times by others too) for some players who dont have a lot of forma. The problem here is forma takes about a day to finish crafting which means I need 5 days of forma crafting to get the forma needed for the weapon.
Now I was looking for a reasonable way to make things easier but still fair for the upgrade. Instead of forma we use Detonite I