Hello Muhammad Saqib,
Thank you for this feature request. Indeed current spell checking functionality is limited to "Change" only and we are not able to provide any workaround for this. We will add this request to our to-do list. However the list of features for the upcoming Q3 major release is already quite full and most probably we will not be able to deliver this feature for Q3.
Let us know if we can help with anything else.
the Telerik team