Ok, just to chime in, I tend to look at this sorta question from Population/Central Places Theorem angle. Patrols will tend to happen along major routes between higher population systems.
Couple that with with the modern practice of Piracy in the modern world. It's not the big slow moving ship with the flaky Transponder that you worry about but the 6 mismatched Smallcraft that happen to be in the area where you precipitated from jump in.
The last bit is that the Jump entry into the system from a common known starting system can generally be worked out It's in those areas in unpatrolled systems Commerce raiders and pirates hang out.
The piracy question I have been pondering is more along the lines of how big a maneuvering unit is needed to do that leap from ship to ship, especially as longer ranges... Consider this said swarm of Smallcraft rush upon our hapless merchant, matching course and unleashing a swarm of Vaccsuited boarders all of which are carrying Hull breaching charges. Remember your average Merchantman can only engage one target at a time...
To circle around to the original question, I really don't see a need to revamp the basic parameters of distance required for jump. My opinion is more of the classic Pirate attacks should be examined and played out, in that the "Pirate Raid" if frequently unmentioned. Note the opining scene of the movie Serenity is a classic Pirate Raid which turns into a Raid by angry natives...