The FSS currently scans a planet and counts the number of Geo/Bio POIs, if present.
Presumably, this can take some time as a result of the FSS actually having to "scan" some kind of database which holds a planet's data.
It's not looking up in a database, the stellar forge is procedurally generating each planet everytime we use the FSS to scan one. It's actually generating and locating every surface POI when the FSS sits there for 10-20 seconds spinning its wheels.
That's why FD is proposing this new probability table lookup mechanic, so they can skip procedurally generating the planet in the FSS.
I'd rather they optimized the code to simply generate the POI tally totals faster. It doesn't need to physically locate the POI's on the surface, the FSS just needs to count them all up. The probes can do the physical location part if we choose to fly there based on the FSS findings.