Lol, the problem was not really the planet. Its all the AI the swarm you while you orbit if not cloaked.
Seems like bombing the planet has become the necessity in order to take it without all the bs.
Btw, I disagree with the idea that a planet would not surrender to a cloaked ship. The whole idea to blockading a planet is it cut off the colonies resources needed in order to survive. Being cloaked would still accomplish that goal. Any cargo ship would simply be blasted out of the stars by a blockading ship and then re-cloak to continue starving the people of the planet.
Why should you be able to take a planet with such ease though? If your blockading a planet, then everyone SHOULD see you. No ones going to just bend over and surrender to a ship thats cloaked doing nothing at all.
Even if you do take your scenario, its so you can hide from AI, but in general, they (AI SHIPS) shouldn't just ignore you, your blockaiding the planet. Instead even still, they would rush you at the planet, because well, your blockaiding the planet. If your blockaiding, then they know you are there. But taking your example, You are more uncloaking to actually blockade, because in cloaked mode, you can't do squat. If you sat and didnt uncloak, how would that be blockading? You are more waiting to 'blockade' rather then actually blockading.
It just seems to me its a cheap way of avoiding AI or death in your statement either or. It's not ment to be easy to blockading, thats whats using colonies is for. Blockading is ment to be tough. And even still, staying cloaked to avoid AI enemy fire would be a 'bug' in my eye because in a sense, no one would just sit and let there planet get capped like it was nothing.
Plus I really don't consider this 'blockading' in a sense, its more like influence, because your not actually 'killing' supplies that go to the planet/etc, your just simply orbiting the planet.