Upasaka Suminda Sirinath S. Dharmasena,
May Atma be able to proper trust that Upasaka is well, healthy any heedfull?
Especially Notes here give further crosslinks, aside of the Sutta it self:
SN 46.054 and a linked in another question AN 04.125
Also Sankhitta Sutta: In Brief
(Good Will, Mindfulness, & Concentration) might be of interest.
And here maybe useful Bhant Nyanadassanas teaching: From mettā Jhāna to nibbāna and a Sutta and commentat that supports that: DN.09 and at least The Limits of the Unlimited Attitudes -
The Brahmaviharas on the Path to Awakening by Bhante Thanissaro with many links and crossreferences.
All collected in "Metta-Boom just fills Heaven and Hell"
Here some of Ven.Mahāsi Sayadaw comments.
In regard of Bhanthe Vimalasiri, best to ask Upasaka Micro, he is surely be found on any forum of other tapapals, charts or equal Buddhist communities and as disciple (till not so long mentioned as such) of Bhante, he always loved to share in this regard.
(Note: This is a gift of Dhamma not meant for commercial purpose or use for other wordily gains.)