There are already deadspace sites that don’t allow lighting a cyno. Simply apply these settings to all deadspace areas. For all its worth you could also disallow the use of deployables and filaments in deadspace. If you want to get your wrecks, you have to come back after the DED sites despawned. The solution to the issue is already in the old code. CCP just needs to learn to read, understand and apply the old code schemes to contemporary EVE.
Even if sites with such deadspace exist(I am just not aware of them), your solution alone wont fix the exploit entirely. Personally Id prefer CCP working on actual gameplay content over fixing unintended interaction between old systems.
there is a threshold on the ESS grid where warping inside of that threshold from elsewhere in the system, will land you at 0 on the gate. Outside the threshold warping to that point from elsewhere will land you on the intended spot instead of at 0 on the gate.
The upshot of this, is that you can jump in high value (eg covert) assets just outside the threshold, move them to within the threshold, and “hide” them on the ESS grid several thousand KM off, and unless the enemy has a ping already in place he’ll have to burn from the gate to get at you. You’ll see him coming from several thousand kilometres off and take measures to evade him (like, cloaking).
I’m not going to tell you what the threshold distance is.