I can't directly answer your question but at present there are dedicated lanes and officers for eVisa entry at DEL T3. During my last two trips the queue for eTV was just one or two minutes vs a very long line in the general "foreign passports" lines. The actual processing took perhaps one minute. It's possible that there were some early teething issues with the process when your wife first visited but right now it is very smooth at DEL. I flew with NH both times.

Perhaps someone else could comment on recent experiences at BOM.