Just for your information while you are formulating your ideas and plans I would like to tell you what my Scan125 Control Program does with regards to logging.
I has 3 basic built in logging functions.
1) A notepad like function where hits can be manually recorded via a button or automatically stored. Also the user can make their own entries and notes:
Scan125 Control Program User Manual
2) Manual and Auto storing of frequencies in a special data array which is in addition to the scanners channel banks: (same URL as above)
3) A separate "Frequency Log File":
Scan125 Control Program User Manual
My users have found these "in one place" facilities of value. Also all the files are plain text / CSV so are readily usable by/in other software.
One user of mine uses EXCEL/spreadsheet program exclusively to manage his frequencies and his own notes. He has many 1000s, far more that the scanner can handle so in his spreadsheet he has many tabs with each tab being for specific frequencies/groups. From any tab he can select one, more or all entries and fire off a macro to built a data file that the scanner can then load. Others may be using some database programs like Access etc.
SO FOR YOUR PROGRAM you might like to consider "building model specific scanner data files" from your program. I think you may have already hinted at this but the devil will be in the detail. By that I mean that the user main operating and input fields and formats will require careful thought and scrupulous integrity checking because these data / fields will be gathered and turned into specific scanner model data files and a single character out of place, or too many will quickly break things. Same goes for frequency formats and ranges for each scanner.
I'm not into trunked scanners so no doubt there are potential issues there as well.
And while you are there another "gotcha" is language and locales. For example in Europe the "," is used as the decimal point.
Hope the above gives you some extra useful information for your program.
Nick