Id like if the Morph option had more options fx, to allow units to morhp for free. This could be used in all sorts of manners, deplyed units VS undeployed, Buildings that can fly, buildings that can gain bonuse when deployed.
The only problem is that in MG, you can only discount resources AFTER the morph has already taken place. So a free morph would require that you still have the resources before hand. The alternative is to implement the same tag GAE has:
<cost-modifier value="" /> (much preferred to use the same syntax to ensure compatibility). This tag discounts resources from the total cost before you morph, so you could put 100 (since it's a percent like the discount tag) to get your free morph, and it's still 100% compatible with GAE.
What's the point of having multiple discounts? Since they're placed skill specific, you can already take off that amount in just ONE discount. Eg, two discounts of 10% and 20% could just have a discount of 30%, and you'd get the exact same results. Free = 100%, so having two discounts of 100 and 2 means that you... get 2% of the resources in surplus?
At any rate, it already exists. As well, you could always make the resource cost of the unit that is being morphed into free. In fact, you can already do that in MG, no changes necessary.
Have fun "free morph"ing.