Surrender Certificate appointments VFS Manchester

Anyone who's had experience of this at VFS Manchester, would you be able to elaborate if they are reasonable with wait times at the centre or whether it's a situation where you are allowed in at the designated timeslot but you may end up waiting an hour or two before your turn comes up?

This is because depending on the answer I'll have to take full day off from work or only half a day.

It's a quite annoying that SC appointments are late mornings and OCI appointments are early mornings, it essentially means I can't make a separate appointment on the same day for OCI after getting the SC receipt and have to take two full days off (I believe you can apply for OCI using SC receipt, you just have to email the SC later when you get it before the OCI is issued, but it's pointless if you can't do both appointments the same day)