The $container_title variable seems to no longer be exposed in JSON UI. No amount of string manipulation or matching will work as of 1.20.30 i.e. 

($container_title = 'Title123')

or

($container_title + 'ABC')

or

(($container_title - 'custom_string') = $container_title)

Steps to Reproduce:

1. Apply the "Chest UI Example" pack attached.

1. Name a chest "blue>Chest title here"

Results:

The chest no longer changes styles, whereas on MC 1.20.15.1 and lower, the chest appears blue as intended.

Screenshots/Videos attached: 

Version 1.20.15.1:

Version 1.20.30.2:

Notes:
There's a very high likelihood this issue is a result of whatever was done to fix MCPE-161134