A provisional note:
Becoming common in RP; general in S. Hemisphere.
lose their final glide and become long monphthongs,
This raises the question of whether they are tense or lax vowels! dress and kit are of course lax (and so always short, at least in RP); but here they appear as long tense vowels, subject to fortis clipping like other tense vowels (compare scares, - , with scarce , (perhaps with half-length )).
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