They are implicitly conditional already: if the AI can't follow some of the availability "advices", it will just ignore them. So I would add them without worrying about it.

NeoAnderson wrote:I think You can use Ai AVAILABILITY block as other blocks, set a variable to 1 when the ability is activated, reset it to 0 when the turn end. Inside the block you check the value and return true when the variable is 1.
This should need tests, I'm not sure if you can use AI_AVAILABILITY the same way as AI_CUSTOM_SCORE... if I were to guess, I'd guess not, but I can't be sure.