latch waits after frequent delete/insert in assm tablespace

Recently, I had a process that performs table refreshes via a delete and insert operation take longer to process due to latch waits and a possible hot block problem.  Given the fact that the process performs deletes as opposed to a truncate, I assumed that there could be freelist contention.  The table(s) resides in an ASSM tablespace and since the blocks are managed with multiple bitmaps, the freelist contention did not seem plausible.  However, I truncated the worst offending table and performed a load test again and the processing time returned to normal.  The developer has been running this process