Tony:
After stipulating that analyzing lines in isolation is a mug's game I'd say that one or two of these examples would be dealbreakers for me if I were an editor or a contest judge.
(x) the /
bland sky / that
bel/lies
down/ at
dusk
IME, dropping syllables usually involves leaving stressed/promoted ones behind. This is more true of lame feet than acephalous ones, though. For example, I wouldn't bat an eye at this one:
The
mu/-shu
pork? / (x)
Chick / en
on / the
stove?
IMHO, this next one occurs too late in the line:
The
li /quid
night/ seeps
in. / (x) The /
glass dreams.
...which, coupled with the missing stressed syllable in that foot, would be too much for me.
Dropping two syllables isn't a problem in trinary rhythms. We see a lot of that in Byron's anapestic tetrameter "
Bride of Abydos":
[x] [x]
Know | ye the
land | of the
ced|ar and
vine,
Dropping an entire foot of a binary might get a reader thinking of het-met and me thinking of the next poem in the pile:
(x) (x) /
bland sky/ that
bel/lies
down /at
dusk
On the plus side, the two separate drops work well in a list:
(x)
mu/-shu
pork? / (x)
Chick / en
on / the
stove?
...as it did for Shakespeare here:
The
best | of
men | have
sung | your
at | trib
utes,
Breasts, |
lips, |
eyes, | and
gold | en
hair!
...noting that neither example involves a 4th or 5th foot.
I could be wrong but I get the sense that you may be applying a principle of accentual meter (i.e. a fixed number of stresses per stich) to accentual-syllabic meter (i.e. a fixed number of feet per stich).
Regards,
Colin