Standard Change - restrict fields to 'read only' only on specific templates

[adminion]

We have a number of standard change templates with predefined journal entries, such as:

Justification
Backout Plan

Test Plan

We would like to make these fields 'read only' for certain templates.

I have tried creating 'read only' UI Policies where the template name is the condition however this does not seem to work. 

Can anyone suggest a way to do this?

[Saurav11]

Hello,

You can update the client script:- 'Mark standard change fields readonly' ased on your condtion.

OR

Also on the templates you will be having the option to add read only fields:-

Please mark my answer as correct based on impact,