With the current game mechanics, you can anchor virtually any structure in any system in 0.0 without holding or occupying the system you put your structure up in. This has lead to some “structure-spamming” .
As sov holding entity, you should have more control of who can anchor structure in your space and the time zone they are vulnerable, via the Ihub. That is, if your space is uncontested.
However, if your system has been successfully reinforced, TCU and Ihub, anyone could then anchor structures in your space. If you as defender gain control again, any structure in system you hold should be vulnerable during time zone of your choosing.
And if people could keep the other issues with Upwell structures such as the damage cap, low-power structure (killing them), tethering, unlimited space, asset safety… out of the discussion, that would be great.