When a field is readonly you shouldn't be able to modify the content of it so the field shortcuts should not work.
With the current behavior you can chang,e for example, the date of a processing sale. (In gtk client you can't)
Steps to reproduce:
- Go to Sales -> Sales
- Create a new sale with a date and go through states until the date field is readonly
- Focus the date field and press "d" key (The date will be increased)
- Save the record and the date will be updated.