Yesterday was an exciting day for me. I was continuing my editing of De Smet's essays on Sankara, and was trying to fill in his references. I came across names such as Tillmann Vetter, Michael Comans, George Cardona, besides already familiar ones such as Wilhelm Halbfass, Sengaku Mayeda and Paul Hacker. I search the net for the bibliography, and it's wonderful how, with some patience and luck, most of the time it is possible to find what you are searching for.
But what was exciting was that I came across De Smet being cited in at least three works:
Comans, Michael. The Method of Early Advaita Vedanta: A Study of Gaudapada, Śaṅkara, Suresvara and Padmapada. Delhi: Motilal Banarsidass, 2000. See esp. 225-231. Comans, however, disagrees with De Smet, feeling that De Smet has too readily assimilated Sankara to Thomas Aquinas. However, he candidly admits that he does not know too much about Aquinas!
Mayeda, Sengaku. “An Introduction to the Life and Thought of Śaṅkara.” Śaṅkara’s Upadesasahasri. Vol 2: Introduction and English Translation. Delhi: Motilal Banarsidass, 2006. See 49, 53-54, 66 notes 14, 17, 28, etc. De Smet himself cites Mayeda approvingly regarding the dating of Sankara and some other points; but Mayeda sticks largely to the classical 'acosmist' reading of Sankara, I think.
Padalkar, Shashikant. “Knowledge and Ignorance: A Student’s Note on Advaita-Vedanta.” 87 pp. http://www.scribd.com/doc/11543653/Knowledge as of 28 September 2009. Reference to De Smet on p. 28: the method of adhyāropa-apavada with its variations is analyzed by modern scholars such as Swami Satchidanandendra, Richard De Smet, Anantanand Rambachan and Michael Comans. No works of De Smet are mentioned, however. Still, this is something to be followed up. Who is Padalkar? Where has he studied? How did he come across the works of De Smet? Etc. Note that he deals with laksana in De Smet's sense too.
I have a feeling that more will be found. Once people like Mayeda begin quoting an author, it is inevitable that others do so too.
At any rate, I have finally come across the motherlode: a list of Indological books (especially on Sankara and Advaita) to be acquired for our library.