A gripe about Lab Texts, beginning with my discussion here: https://forum.atlas-games.com/t/lab-text-restrictions/6985/1
It seems extremely counter-intuitive to me that a magus who has previously created an magic item, greater or lesser, cannot later use that lab text to instill the same effect in his own talisman. That, in fact, you cannot use any lab texts, ever, to instill effects into your talisman, unless you're rebuilding your talisman from your own notes.
The more I read the restrictions on Lab Texts for enchantments, the less sense they make, particularly when I focus on the sentences around "or vice versa."
At the very least, I think having a lab text for a similar enchantment should provide the sort of bonuses spells have for knowing similar spells, even if the previous lab text was for a lesser enchantment and the current work is for a greater enchantment or talisman. Come to that, I think that having a lab text for a similar spell should provide the same bonus as if you knew the spell in question), particularly given how often they emphasize that you're really inventing a brand new spell from scratch based on other people's notes.