There had been different ways the validation error/warning messages are being displayed on the browser at different pages. With the 2 ways design display it would not align the consistency of presentation. Old way of Pop-up windows would be really great and enabling the type of display if given control to tech consultants for configuration at profile level would be more useful and align with customer requirements. This has been already discussed in the Syniti Support ticket #48319
We will consider this in terms of consistent approach to validations and message pop ups in the new Contruct component in the SKP UI but are unlikely to make any changes to the SST at the present time around this topic area.