user120938: According to BIP-341, the control block can have a length of 33 + 32m, for a value of m that is an integer max 128. Does it mean it's possible to construct a MAST with 128 levels, making 340282366920938463463374607431768211456 possible script combinations?

user208: That's correct.
Of course, that many leaves is intractable to construct. The reason for permitting that many levels is to permit unlikely leaves to be put in deeper levels, reducing the average control block size (while increasing the worst cast control block size).

120938: <p>According to <a href="https://github.com/bitcoin/bips/blob/master/bip-0341.mediawiki" rel="nofollow noreferrer">BIP-341</a>, the control block can have a length of 33 + 32m, for a value of m that is an integer max 128. Does it mean it's possible to construct a MAST with 128 levels, making 340282366920938463463374607431768211456 possible script combinations?</p>
 208: <p>That's correct.</p>
<p>Of course, that many leaves is intractable to construct. The reason for permitting that many levels is to permit unlikely leaves to be put in deeper levels, reducing the <em>average</em> control block size (while increasing the <em>worst cast</em> control block size).</p>
