The issues isn't with the SAPs, it's the same old problem, of not enough players active in the game.
This is a global, open world game. Time zones are always going to be an issue. If corps can set thier intrusion times, the server will divide roughly into (3) 8 hour groups; US/EU/Asia. I don't think allowing the server to segregate in this way is desirable.
Undefended SAPs or players just going in to ninja the loot aren't relevant, its certainly a mistake to try to balance the Intrusion system around scenerios where neither side really cares if they keep or get the outpost.
Therefore, the only interesting SAP scenrios are ones where attackers show up to, with the intent of taking the SAP, and there is a force willing and able to defend it.
Intrusion defense is boring for 93 minutes, if no one shows up for it (or they detect they are greatly outnumbered): Login 30 mins prior to defense, stand around for 60 mins, grab loot, dockup and logout.
Intrusion Attacking is boring for about 60 minutes, if no one shows up to defend it: Login 10 mins before intrusion, wait 15 mins for stragglers and refits, travel 10 mins to SAP island, scout for 5 mins, take SAP in 2-12 mins, travel 10 mins back to outpost and log off.
Intrusion defense is boring for 45 mins, if too many attackers show up for it: Login 30 min prior to SAP, assemble and detect, see 4x your force jump in 10 mins after SAP starts, 5 min to dockup and log out.
Intrusion attack is boring for 50 mins, if too many defenders are present: Login 10 mins before intrusion, wait 15 mins for stragglers and refits, travel 10 mins to SAP island, scout for 5 mins, see outnumbered, travel 10 mins back to outpost and logoff.
When numbers are fairly even, then its exciting. Not allowing the attacker time to manuver, that is reducing the open SAP time, would mean the only way to ever win an intrustion would be to show up in overwhelming force, that allows the attacker blitz in, wipe or push defenders off the SAP and then camp the outpost to stop zerging.
Which leads back to the scenrio where attackers show up with 4 to 5x the numbers, because they have to.
As boring as it is, and I know how boring it is to sit for an hour, the game has to allow attackers time to manuver around, use terrain, and attrition to gain the SAP. And it is most certainly NOT a boring hour when you are in a SAP battle.