If you have indexes on destination tables, please drop them before transfer data and create again after.
Keep Identity - by default this setting is unchecked which means the destination table (if it has an identity column) will create identity values on its own. If you check this setting, the dataflow engine will ensure that the source identity values are preserved and same value is inserted into the destination table.
Keep Nulls - this setting is unchecked which means default value will be inserted during insert into the destination table if NULL value is coming from the source for that particular column. If you check this option then default constraint on the destination table’s column will be ignored and preserved NULL of the source column will be inserted into the destination.
Table Lock - by default this setting is checked and the recommendation is to let it be checked unless the same table is being used by some other process at same time. It specifies a table lock will be acquired on the destination table instead of acquiring multiple row level locks, which could turn into lock problems.
Check Constraints - this setting is checked by default, it's highly recommended to uncheck it if you are sure that the incoming data is not going to violate constraints of the destination table. This setting specifies that the dataflow pipeline engine will validate the incoming data against the constraints of target table. If you uncheck this option it will improve the performance.