Edge doesn't let you take a 6th IP. Hell, Edge won't even give you the 5th IP you get from the simsense booster/simsense accelerator combo.
I thought the hard SR4A ruling specified: No character can get more than 4 IP.
Is there a rule I've missed somewhere that trumps this?
TMs and hackers can get 5 in the matrix without using edge.
p.147 unwired Advanced Overclocking
Prerequisite: Overclocking
Advanced Overclocking has the same effect as taking
Overclocking twice (counting the prerequisite echo). Together with
the Overclocking echo, the technomancer receives a total bonus of
+2 Response and +2 Initiative Passes while operating in full-sim VR
(with the 2 extra Initiative Passes from hot-sim VR, this grants the
technomancer an IP of 5; this is an exception to the rule that normally
limits IPs to 4).
And p.198 unwired
Simsense Accelerator
This state-of-the-art mod increases the speed at which simsense
signals are transmitted between the commlink and a persona controlled
via hot-sim VR. It increases a VR-using character’s Matrix
Initiative Passes by 1. It does not boost Matrix Initiative in cold-sim
VR or AR. It is compatible with simsense booster cyberware (so a
hacker in hot sim with a simsense accelerator and simsense booster
cyberware has 5 Initiative Passes). Initiative Passes; this is an exception
to the rule that normally limits IPs to 4).