ps umbraco forms does already add the fieldtype as a class and the sanitised field name, and the guid as id for the unique per form property.. if that’s enough for css targetting I’d go for leveraging that..
eg DatePicker FieldType
(you can set a custom css file to use rather than the default per form) Form Settings | Umbraco Forms
The problem with themes comes when you update uForms.. you have to remember to manually check for any update to the core theme and revisit your theme.
It could be mitigated a little by UForms, moving the business logic out of the view… but as the override is nice I get why it’s there as providing extension points to overwrite code from a dll would make things harder. (as updates usually change the code and not so much the markup..
this part is what I mean…
So I’d say if it’s just css.. then avoid.. if you need to change the markup then this is your only option.
But that’s the problem with the whole RCL package and overrides.. you simply take a point in time snapshot of the package code and change to your own.. detaching the package in a way…