Namaskaram Swamiji

I am staunch follower of you and I used to listen what’s app speeches and other upanyasams through media.

I have a doubt and it was asked by me last time. Some how it did not reflected in the Dharma sandeha.

Now coming to the point that Sri vaishnavites neither learning nor chanting SriRudram, Chamkam, Kumara suktam, durga suktam etc., even though it is part and parcel of vedas and Sri Krishna time and again told in BG that HE is  the essence of vedas.

I would like to know the reason behind not praying other Gods except Sriman Narayanan. Is it correct to neglect portions of vedas? Rishis like Viswamita , vashister, agastiyar prayed Sri Rudra, Ganesa , Subramania and other goddess.

If we pray other gods other than Sriman Narayana we will not get moksham. I would like to know the reasons not otherwise.

Kindly through some light on this subject.