Quality of /E/ in Scottish English

I've heard a lot of Scottish people use what seems to be a very close realization for /E/ - for example, just today on TV, I heard a Scottish person say "less", and the vowel quality sounded like [e]. I wonder, why is this? I know that Scots tend to realize the GOAT vowel as [o(:)], and as a result, they tend to have a LOT-THOUGHT vowel - [O] or [Q] - that's opener than the THOUGHT vowel of RP. So why doesn't this seem to be the case with the FACE and DRESS vowels - ie, a very open realization of /E/? And as a followup, is there a merger of the FACE and DRESS vowels for some Scots? From some Scots that I've heard on TV, it seems quite likely to me.

And another phenomenon that I've heard in many Scottish English speakers is a very open realization of the KIT vowel, /I/, as something like [E]. Maybe once the DRESS vowel has become more close (and possibly merged with the FACE vowel), then the KIT vowel becomes more open in order to fill up the gap in the vowel space?

So has anyone else noticed these things? It just seems to me that there may be some features of Scottish English phonology that get ignored in the standard descriptions.

Mind you that such a pattern with the FACE and DRESS vowels versus the GOAT and THOUGHT vowels is not uncommon in North American English dialects which are not cot-caught-merged. In such NAE dialects [E] will generally be markedly closer than its counterpart [Q] (albeit not as close as you indicate the DRESS vowel often is in Scottish English). Even here, where the DRESS vowel is actually very open (to the point of approaching [{] in openness), it is still closer than the THOUGHT vowel (which effectively has the same POA as the [A] in "car" here).

If quality does not help to avoid a merger, in this case quantity cannot either. Given the Scottish Vowel Lenght Rule, /e/ in FACE should be short and /E/ as in DRESS is always short regardless of context. We should hear from Damian to settle this.

Is there any kind of difference in frontness that is present here? This, for instance, is what keeps progressive DRESS pronunciations from merging with more conservative TRAP pronunciations here and conservative DRESS pronunciations from merging with more progressive FACE pronunciations. The matter is that DRESS is almost central (approaching [3] or even [6] in everyday speech) here while FACE is uncentralized (but in everyday speech may even approach [E]) and TRAP is uncentralized or at least has an uncentralized nucleus (in the case of [E3_^]). In this context, frontness is a key distinguishing factor for keeping DRESS apart from both FACE and TRAP. (Of course, then, in unstressed positions in unstressed everyday speech DRESS and TRAP may very well merge at times here.)