According to Wiedenhof's A Grammar of Mandarin, page 25,
When following a frst or a second tone, and simultaneously preceding a non-neutral tone, a second tone is pronounced with a high level pitch 55 (high to high), i.e. as a frst tone. This diference can be represented in Pinyin: ānmián yào ~ ānmiān yào ‘sleeping pills’.
Does "represent" here mean that, instead of the citation/lexical tones, the new tones after tone sandhi can be used as well?