Yesterday, I finally managed to code something what could be taken as improvement for Sony-Ericsson phone owners. My Gammu branch can now read complete phonebook entries. The implementation is now far from being effective, but works good.
What needs to be improved is way for getting LUIDs, as reading complete phonebook just to get list of all LUIDs is big overhead and causes big slowdown when reading first entry. Parsing IrMC changelog might be a solution, but it would need removing of deleted entries, what is harder to implement. I will try to investigate this possibility later, as this is not required to be handled right now.