Lutelyse opens the cervic in a doe and expells the contents, no matter what the stage of pregnancy. Well not the first several days, because the fetus are not attached yet.
We have routinely used lute for years, when we where CAE positive back in the late 80's. All does where given lute, they kid approx. 36 hours after the shot. This way I was right there to catch and remove kids. If you do not have a good due date, you have kids in 36 hours, ready or not, I have seen kids born whose due dates where 3 weeks off, induced by lute, and unviable.
It is also used routinely used, in alot of show farms. Does are bred their first year, because of birth hormones the kids grow quicker, they are aborted about 80 days in, so there is no udder formation, they then can be shown in 12 to 24 months, as big dry yearlings. I breed my does to kid on their first birthday, so I have never followed this practice.
The only thing dex will do in a pregnancy in a goat is to mature the lungs of kids. This was part of the old, erronious information that used to be given about all metobolic disease in goats, always called ketosis. We now know few goats really get ketosis, so aborting them early, using dex to mature the lungs, isn't done very much anymore. (It is widespread information on the Boer lists, they use Lute and Dex together always, they also use penicillin after every kidding if they even touch the doe.) We now know about hypocalcemia, and treating for this, before they go down. Also with CAE prevention, most routinely do not use lute for kiddings (dairy goats). It's a nice tool to use when it is given correctly.
My vet, also a Merry, wasn't really thrilled with our use of it in the beginning either, she now has seen it's use over the last 18 years, and now knows how well this drug works for goats.
My advice is rarely about what someone else has said does or does not work. Other than my list, where I of course chat about everything, most questions I answer are things that directly have worked for me. Vicki