[MCM-927] Ridden Entity Teleport and Movement does not Work Properly

Verification Builds: 1.14.20, 1.14.1, 1.14.0
Summary: When a player is riding an entity (boat, horse, custom entity..) the player location is not accurate and in the case of teleporting the entity far away it does not teleport the player riding it.
Reproduction Steps:
1.- Generate a new super flat world with Simulation Distance set to 4 Chunks (to match realms sim dis) and run this 2 commands to make a long blue ice path

/fill ~ ~-1 ~ ~300 ~-1 ~3 air
/fill ~ ~-1 ~ ~200 ~-1 ~3 blue_ice

2.- Get a repeating command block and set this command on it

/execute @a ~ ~ ~ execute @e[type=boat,r=0.025] ~ ~ ~ say in_boat
Repeating, Unconditional, Needs Redstone, Delay in ticks: 0

3.- Attach to it a chain command block with the following command

/say tick
Chain, Unconditional, Always Active, Delay in ticks: 0

4.- Make a tickingarea to have the command blocks always loaded

/tickingarea add circle ~ ~ ~ 4 commands

5.- Get into a boat and activate the repeating command block with a redstone block and start moving with the boat, you will notice that when moving at high speeds in chat only displays one command ([!]tick) and when you stop moving and you start slowing down both messages appear on chat

Watch video_1 for a visual demonstration

Watch video_2 for a visual demonstration with a custom entity
if you pay attention to player and entity shadows you will see that the player shadow is not always at the same distance of the entity.

6.- Break the redstone block to turn off the commands, and remove the ticking area

/tickingarea remove_all

7.- Get into a boat out of the ice path and run the following command

/execute @e[type=boat,c=1] ~ ~ ~ tp @s ~100 ~ ~
You will notice that the boat gets teleported with the player on it

8.- Run the next command

/execute @e[type=boat,c=1] ~ ~ ~ tp @s ~1000 ~ ~
You will notice that player screen flashes (trying to teleport to that coordinates), but the player will remain in the same coordinates but the boat will be in the teleported ones
teleport to those coordinates to verify the boat is there
/tp @s ~1000 ~ ~
You will see the boat there

Watch video_3 for a visual demonstration

Expected behavior: Player should always be in same position when riding an entity and teleporting an entity with the player riding it should always teleport the player with the entity and not only the entity

Impact: affect the release of a minigame using the teleport entity feature

Notes: it can have a semi-workaround if the entity is teleporting to a long distance and this is in a ticking area it will teleport the entity, but not all the times, only some of them.
Tried to run the command constantly to teleport the boat to the needed location but in case multiple players are playing the minigame as at first attempt the boat tries to tp to the location but fails and as it has been at that location for a little ammount of time (less than a tick), and the command continued running the nearest boat to the player that should be teleported to that location is another player boat which at the end will result on a teleport of both players to the needed location even that the second players should have not been teleported.

Attached Video:
(hosted in streamable)
video_1
video_2
video_3