Will you consider using ASP.Net Ajax Update panel as a solution? It supports partial page postback
. You may put your web element inside this update panel, which is triggering the postback and the controls which are getting rendered as a part of that postback.
Please note that you will have to add AJAX Script manager
at the top of the page to use update panel feature.
Use this link
as guide to use AJAX update panel feature. Postback flickering will be reduced to a minimal zero after implementing this.