I see no reason given this precedence that your interpretation should be considered correct, especially given the ramifications to game balance.
Very nice, very nice indeed. You have just one rather tiny flaw in your argument. What I've stated is not an "
interpretation". My source is a word-for-word quote from the latest edition of the core rule book. This is a clear statement of system functionality written in plain, properly grammatical English. That trumps
any hazy and equivocal reference you may be able to pull from another source.
The hard-cap for IPs
is 5. No ifs, ands, or buts about it. Do not pass go. Do not collect 200¥.
Underline,
bold, CAPITALIZE, and
italicize all you want, it's not going to change that fact.
I don't know what the guy that wrote Simsense Accelerator was trying to say or prove, or what he was smoking when he wrote it. All I can possibly conceive of is that it was meant as an assurance that it
does stack with Simsense Booster, and just got phrased in a piss-poor manner.
However, going back and looking at the
Infected Attribute Modifier Table in the Runner's Companion (p79) I do see now that the IP boost doesn't stack with other forms of "IP augmentation", so while I am still correct that the potential hard limit is still 5 IPs, the Vampire could not achieve such a state because his HMHVV boost doesn't stack with the Adept Power, and for no other reason.
P.S. The word you were looking for is "precedent". Precedence is used for relative description, with one thing "taking precedence over" another, like the explicit rules in the core rule-book taking precedence over a vague allusion in a supplement.