Deathstar POS setups since the ECM changes

What is the best way to make a large POS as close to unkillable as possible? The ECM changes mean that you can still target the control tower even if the POS is jamming you, so a dickstar setup with dozens of ECM batteries is just about disrupting the enemy logi rather than preventing them attacking altogether.

We have gone with a large control tower, with shield hardeners so it’s 68/68/68/71 resists, 70 sensor dampening batteries to prevent an attacker sitting at range, over a hundred small and medium pulse laser batteries , various ECM and warp disruptors and webifiers. Obviously the power grid doesn’t let us online all of those batteries at once but the idea is to have lots of reserves so that we can bring new batteries online as other ones are destroyed. We are always looking to see if we can improve our defences and I would like to hear any suggestions

Curious to know if you found your answer

The best you can hope for is to make it as annoying as possible for people to attack.
You have the right basic idea. Lots of hardeners and guns.
Short of anchoring enough mods around the stick to crash or severely lag out anyone warping to the grid*, any pos can be killed if someone is prepared to make the effort.
*note: this tactic will also make the pos unusable by you.