Yes. When a spell shield is on the unit, it blocks the next incoming enemy ability and triggers the cooldown. The trick is that you can make a fake by converting your ability to a spell shield using the engineering upgrade ability.
Add the engineering upgrade, trigger the spell shield with a dummy cast, remove the converter so the ability regains it old shape but the cooldown remains. Depending on the spell shield you change into, you can even have a variable cooldown.
The big problem is that engineering upgrade causes a fatal error when applied to non-heroes. There is a possibility to temporarily/instantly morph the unit into a hero but morphing comes with some downsides, it is not as effectless on a unit as a spell shield.
I tested and talked to Xonok again. It is not that simple after all. If you convert your ability->spell shield, the spell shield behavior is not transmitted, only the UI. So engineering upgrade does not work there. Instead you have to hide/remove the ability, add a spell shield that either has the right UI (looks like the original ability) already or you convert spell shield->original ability. Then trigger the spell shield via dummy cast.
For passives it should be okay, only that the spell shield on cooldown is an active skill and therefore the button is clickable through the cooldown (without any effective order/cast).