The firework rocket use statistic doesn't count rockets used for elytra boosting

The bug

The statistic minecraft.used:minecraft.firework_rocket is incremented when a firework rocket is launched normally, but not when it is used to boost an elytra.
There appears to be no reliable way to detect the usage of a rocket as a booster using commands.

Steps to Reproduce:

• Run the following commands:

/scoreboard objectives add firework minecraft.used:minecraft.firework_rocket
/scoreboard objectives setdisplay sidebar firework
/scoreboard players set @a firework 0

Launch a firework rocket on the ground normally.
→ The scores increased by 1.
Fly with an elytra and boost yourself with a firework rocket.
→ The score does not increase.

Code analysis

Code analysis by randomdude999 can be found in this comment.