Both sides can be argued, and it may vary from saga to saga: Making the text verditius-only will make them all the more precious. I can very well see lab texts for items being quite rare, save verditius lab texts, that are worthless to non-verditius. This makes a MC more special, which is cool!
Overall, unless a MC is important in a given game (like, you've got a verditius player with easy acces to texts), given the scarcity of lab texts for items, it's probably better for the sake of the game to have them being able to be used by anyone... You just have to decide that some components are critical to the process (namely, those in the lab text paragraph), whereas others are optionnal and just make your work easier.
=> I guess you can have something like "Take a sword of the finest metal, engrave it with the runes of destruction, and dip it 3 times in blood while the full moon is in effect. Then, for 10 days, 6 hours per day, recite the following incantation over it (incantation follows), while your forge companion tempers it again in the forge"
If a magus doesn't know what the runes are, or doesn't have a forge companion, he can still create the sword, it'll just be harder. Likewise, a magus with Positive Cyclic Magic (Autumn) would see his incantation's strengths bolstered by that season, whereas one with negative CM would see their strength decreased, but so long as it is enough, the enchantment would work.
As often, YMMV 
Now, if a magus is unable to use some critical part, he's toast.