SAS drive: background media scan vs smart long test

Question

My SAS drives do a background media scan (BMS) every two weeks:

[root@universe ~]# sdparm -a -l /dev/sda |grep BMS
  EN_BMS        1  [cha: y, def:  1, sav:  1]  Enable background medium scan
  BMS_I         336  [cha: y, def:336, sav:336]  Background medium scan interval time (hour)

I also do short SMART test every day and long SMART test every week. This is configured in /etc/smartd.conf

DEFAULT -m <email> -n standby -a -I 194 -I 231 -I 9 -o on -s (S/../.././02|L/../../6/07)
/dev/sda
...

I would like to know how a smart 'long test' is related to BMS? Are they doing the same job? Does it make sense to run both of them?

After reading this article about BMS it looks like BMS is way more advanced than SMART test. At least for SATA drives SMART long test is just a surface scan that report first read error. Is it the same for SAS drives?