Hi Magesh,
This is a serious and significant problem. I think nguyen just didn't provide enough detail about his "template"
If you take the sample from the SyncFusion Grid documentation
Grid Editing (Template-driven Forms), you can see this problem.
For a quick test, I took the sample project you linked to and then pasted the code from the Template-driven Forms example into app.component.ts and app.component.html.
You will need to clean the sample code up a little, as app.component.ts has no 'pageSettings' field that template-driven.html references, and it won't compile because AppComponent.data and AppComponent.orderData are not of type IOrderModel[] and IOrderModel respectively.
BUT once you have it all cleaned up and properly building and running...
Go change the html inside the ng-template (maybe change the label "Order ID" to "Order FOO ID". You will see that the Grid is not actually using the ng-template at all.
And worse, if you
disable Ivy with "angularCompilerOptions": { "enableIvy": false } (and rebuild), the Grid completely ignores your e-column statements and displays all fields