Simple, Powerful Leveling Technique, Fastest Method 30-50 (Patreon)

Patreon Mark Robinson sent me the following technique: 

Hey arch , I havnt seen this mentioned anywhere but pretty sure it wouldn't be a secret, if you don't use chromie time then classic world mobs cap out at 30. So you can complete quests very easily , but don't turn in you then change to chromie time ibl use outland but probably works with all others and the old world then scales and you can turn in the quests with full level appropriate xp and approximately  5 gold more per quest hand in at least at my toons level of 37 , good way to get easy levels between 30 -50

So, we would do something like this:

1) Complete the requirements from a quest in vanilla/classic content in the old world with your character at level 30 or higher. This can be done very easily as you outlevel content eg a level 35 character can complete a level 30 quest very easily as you will one-shot every mob. 

2) Now join a group with and turn on party sync with a character with some form of timewalking switched on. This can be a starter edition character. (EDIT: see Mark's comment below)

3) Turn in quest and receive full experience. 

This is currently the fastest known leveling method from 30-50. 

(I published a similar method to this on this patreon and in a public leveling method in bfa, but the scaling changes in Shadowlands have changed some of the numbers and details which Mark has kindly provided. )

*My normal internet connection has been accidentally severed by telephone engineers, consequently I have had some difficulty accessing patreon and publishing articles recently.  Despite this, I will make sure there is the normal amount of quality articles by the end of the month.