I am also suffering from this same issue. Block name conflicts interrupting automated file inserts.
Because I don’t care about preserving block information, my solution right now is to explode all block instances and delete all block definitions before each _-Insert using this function:
def explode_and_delete_all_blocks():
blocknames = rs.BlockNames()
for bn in blocknames:
instances = rs.BlockInstances(bn)
for inst in instances:
rs.ExplodeBlockInstance(inst)
rs.DeleteBlock(bn)