Not sure if any dev is watching this thread but I have made suggested source code changes to bitcoinrpc.cpp from this forked repo branch:https://github.com/ciyam/bitcoin/tree/opt_use_sent_to_addr_for_acc
As I don't have boost or the time to get it and other libs installed at the moment this has not even been compiled (so I have not submitted a pull request).
If any dev (or anyone else) has enough spare time to at least compile and show any errors in my changes then I'd appreciate it.
The change is to the bitcoinrpc command listtransactions whose usage would become as follows:
listtransactions [account] [count=10] [from=0] [usesenttoaddresses=false]
When usesenttoaddresses is set true then the account mapping for "send" category tx's is to the sent to addr (rather than the current behaviour).
EDIT: Link for commit changes:https://github.com/ciyam/bitcoin/commits/opt_use_sent_to_addr_for_acc
I do hope to find more spare time to actually compile and test this myself but unfortunately I don't see that happening for quite a while so once again if anyone else has any spare time to check this I would appreciate it so I can then create a pull request.
EDIT: I will start a new thread in the Development board about this and will put a BTC bounty in that.