I'm looking forward to hacking being revisited. I'm sure you'll manage balance however you do it and it certainly has a lot of potential to spice-up the game but I thought I'd ask:
Why not use AIP-floor rather than total or effective?
One key benefit would be that after killing one AI's home (and the core guard posts) the other AI would be too distracted to notice your hacking... it would give you a chance to win (via hacking toys) if you don't manage to attack both simultaneously. Another benefit is that the range is smaller, and therefore easier to balance, unchanged by DCs but yes CPs would matter (but that isn't a bad thing). Third is that if you can lower AI-floor (through hacking) doing so would further increase the effective hacking response... self-balancing that sort of additional mechanic.
Also, why multiplier? Perhaps use an armour like subtraction. (people like to hug the floor, it's optimal and people like to play optimally... or kill everything and bring on the apocalypse)
e.g. AIP-floor of 50
Effective hacking = (Total hacking - AIP-floor) or Hacking-floor whicher is higher.
(hacking floor could just be 20 or 30%, like armour, or use similar maths as AIP-floor... with certain hacking things raising it... people already are used to Total, effective and floor so no really new terms)
The current hacking responses, 'total hacking' would need to be scaled down to ~0-300 sort of range, something akin to AIP. But since number inflation is something you want to avoid anyway it isn't really a problem.
Perhaps have clear cut changes in the response every 50/100 effective hacking? Similar to the new ship type with AIP:
Tachyon bursts, EMPs, botnet golems, zombie warp-counterattacks, unleashed hybrid experiments, experimental zombie ships... spawned zombie eyes... lots of nasty options
Give some a countdown so you can panic, yell, spill your drink and then quickly shut down your hacking attept when you're warned but completely unprepared.
If the response changes every 100 then hacking below 100 could be considered 'relatively safe'. Each hundred would introduce a new, potentially scary unknown. (Though you would be warned by the afformentioned countdown so you don't have to reload).
Anyway, look forward to any planned hacking changes. I think the game flourishes because of the choices it presents. Choice: clear and meaningful, balanced and intuitive... makes the game great.