Apart from Kshatrabhandu, Muchukundan, Vibhishana, Katvanga, are there others who have performed Prapatti on their own volition (svanishtai)? Is there any reference on this in Ithihasas and Puranas?

Even Swami Desikan describes those who have performed svanishtai in the Adaikkalapatthu pasuram “kaagam iraakadan mannar kaadali kattirabandhu”. Puranas refers to many such as Gajendra, Devas, Vibhishana, etc. To know more details on this question, listen to the discourse available through this link