Alkene addition moiety shifts

[planetme]

Larger/more complex alkenes may experience hydride or methyl shifts during certain reactions such as acid-catalyzed hydrolysis to produce more substituted (and thus stable) intermediate carbocations.

You could probably implement this logic by checking the degree of substitution of the neighboring carbon to the highest degree carbon of the double bond (or both carbons, if equal substitution), and if it is greater than the highest substituted carbon atom in the double bond, move the least bulkiest group of that neighboring carbon (typically a hydride or a methyl group) over to the less substituted carbon atom in the double bond.

[planetme]

The logic could probably be optional using a boolean so that reactions such as oxymercuration-demercuration can bypass this.