Abm scans NIT, SDT and BAT of the home channel transponder (as defined in the provider XML). For most providers it is enough to get the complete channel-list.
However there are providers (mostly the DVB-T providers) who only have service information of the channels broadcast on that transponder. Therefor you need to scan multiple transponders to get the complete channel-list. ABM has that kind of options.
We do a lot of DVB stream analysis to create a good working provider xml.
Using the so called 'hack' functionality in the XML you can e.g. strip transponders for a specific provider / transponder, without changing the source code of ABM.
I don't understand this part:"It is a pitty that it is a plugin instead of an improvement of the fastscan plugin..."? it's a pitty it is a plugin instead of another plugin?