You could add onchange nanoflows that are doing a validation and that show validation feedback.
This would be a really complex setup, with lots of conditional editabillty statements on your inputfields.
Like a statement on fieldB like if $currentObject/fieldAIsValid
On fieldC $currentObject/fieldBIsValid and you need to keep these booleans updated everytime you enter or leave an inputfield.
Thanks for the responses, i got this resolved by running a microflow that only refreshes the object , but only on that widget and non-blocking . below is a screenshot, i run the flow on leave and on press enter key.
This validates the field and gives a validation message immdly, so at least the user now know its entered incorrectly.