I was thinking about my mind block yesterday and some things still bother me.
The example in the book about alternate form assumes a human that switches between a cuddly critter, and a troll. There is no double dipping. The human template pays for the alternate form, the alternate form does not pay for shape-shifting back into the human. The 15 points pay for both ways.
I'll rename Invincible Leonard to PowerLeo nard (PL) to avoid confusion. Strong Leonard (SL) has three alternate forms, PL, IL and HL.
The funny part about Leonard is that all his three forms have themselves as alternate forms. I'm ok with that, even though I can make 50 cp availabel on all three templates by removing the alternate forms advantages. The advantage is that Leonard can switch between his three forms within a second.
I am not even sure anymore whether or why you would need the SL template. However, I like it and fits the concept.
The strange part is that SL is never mentioned as an alternate form. It isn't necessary, as shown from the example from the book. Leonard can always switch back to his previous form, and he starts as SL. I assume SL is his base form.
Now suppose the following day in the life of Leonard.
SL goes IL goes PL fights, saves girl of his dreams, falls in love, goes HL, heals girl and himself, goes IL to save girl, goes PL to defeat boss. Then he ends up into bed together with the girl of his dreams in a very romantic moment. Girl snuggles her head on Leonard chest and says: 'There is no no need for barriers my love, show your real self'.
HL cannot go back to SL. The only thing he can do is
let go of PL, becomes IL
let go of IL, becomes HL
let go of HL, becomes PL
let go of PL, becomes IL
let go of IL, becomes SL.
This process takes at least 5 seconds. If the girl of his dreams shows up after a few months it might take hourse, while Leonard continuousely switches form before the eyes of a bewildered girl. And we're lucky that all Leonard forms look alike (except for the invisible part.).
So the GM would either handwave that or Leonard should take care to shift to his SL form before going to bed every night in order to avoid an alternate form stack overflow error