My question is regarding the lock time of monero transactions. If I want to send transactions from one subaddress/account to another within the same wallet, is it at all possible to set the 'unlock_time' option so that there is no 10 block waiting period? I figure since this is a constraint of the wallet not of the protocol it should be possible. However my assumption is that it's not possible to explicitly set the way 'fee' is ignored and automatically calculated despite being exposed to the user as a configurable param. I have tried passing '0' into unlock_time but it did not appear to have any effect despite the documentation saying "set to 0 to not add a lock". Am I doing something wrong?
The unlock time in the rpc tx field is different from the standard ten block unlocking time.
If you want your funds to be immediately spendable you need to modify the CRYPTONOTE_DEFAULT_TX_SPENDABLE_AGE in the config file and recompile the wallet:
The unlock time field in the rpc tx is something else to keep funds locked for longer time periods. See the answer here:
How to use unlock_time?