Hi,
I took inspiration from this tutorial to successfully add some fields to the mass update for a custom module.
However I am noting that, if I enable text fields, for example, only those created in the original module are taken into consideration and not those that have β_cβ in their name, added later by studio.
So, for example, I tested for text field.
description which is a standard field is shown but my βtext_cβ custom field is ignored. No HTML is produced.