Cannot custom spawners with nbts

Cannot customise spawners, because we cannot put nbt that makes the spawner spawn by example: a zombie with diamond armor or a skeleton with no ai + a custom name + at a different position, almost like java. the Properties in SpawnData in the spawner (NBT) doesn't get used, but it's still there, I really want to be able to use a spawner to spawn custom entities

video show case of the problem: https://streamable.com/tc84jl

 

Steps to Reproduce:

       (This one may not be a great explanation of the problem)

1. Get an egg with a custom name
2. Put in a spawner

       OR (But this one is)

1. Create a spawner with some Properties in the Compound SpawnData in the Parent tag of the Spawner

Observed Results:

• You will see the spawned entity, will not have the nbt

Expected Results:

• The nbt gets copied over the entity when spawning with a customised spawner, example: a zombie gets armor when spawned in that spawner.