Sorry about the bad advice you got from the endocrinologist vet. There are a few specialties within endocrinology, perhaps the one you talked to doesn't have much diabetes experience.
First, I'm glad you didn't listen to the part about increasing by a full unit. A half unit might be OK now, but as you get into frequent nadirs in the low 200's or under 200, you will have to go to 0.25 unit changes. I do agree with the vet about testing 4 times per day. I did typically at least 5. Look around at other people's spreadsheets, you'll see what can be happening between the preshots that night be surprising. The first time Neko went under 50, her AMPS was over 400 and her PMPS was over 300. Without that mid cycle test, I wouldn't have caught how low she was going. Just as I have no idea how low the 2.5 unit dose was taking Coco. Those extra two tests, one in the AM and one in the PM are for Coco's safety. Stress of pokes does not change blood sugar values, as long as you are relaxed too. Try singing to her. It relaxes you too.
Somogyi is not fake, it is different from a bounce, but it is also something that very rarely happens in cats on long lasting insulins when they are started on a low dose, increase by appropriate amounts, and the caregiver is home testing. Somogyi was a concept written for a local journal and was not peer reviewed. It was written almost 100 years ago, based on a small study of humans and old very fast acting insulins. There has been research on Somogyi in cats using Lantus - it is very rare. Unfortunately, it has been taught in vet schools and something especially older vets believe.
The process here is test, feed, then shoot, sometimes referred to as TFS. All within about 10-15 minutes. For the older fast acting insulins, you did have to make sure the cat has eaten well before shooting. Glad you aren't following the advice on this one.
The Lantus depot takes 5-7 days to build when you first start insulin. If you are following TR, you can increase as soon as 3 days later if the nadirs are above 200. Ignore the part about taking into consideration the bounce. TR, should you be able to follow it, has built in time frames for increasing based on possible bounces. For nadirs below 200, doses are held longer. If you are following SLGS, you hold the dose for 7 days, unless she goes under 90, regardless of the nadirs.
I am glad you are switching back to the DM food, but be very careful and monitor closely. The diabetic food is lower carbs and will impact her blood sugars. We suggest trying the new food for a new days, seeing how it impact blood sugars, then increasing if still needed. You can not feed the DM dry food if you want to follow TR for dosing, TR requires and all wet food or dry diet. The dry is too high in carbs for a diabetic. Both it and the wet food are called diatetic, not diabetic management. There is nothing special in that food for diabetics.
Please also ignore those dosing guidelines she gave. We dose based on the nadirs or how low the dose is taking the cat. As I said above, Neko (more than once) went below 50 about 7 hours after the shot when starting her cycle at 400. That would be extremely dangerous to have increased the dose by 1 unit as the guidelines the vet gave you said to do. The guidelines the vet gave you are yet another clue she is more used to the faster acting insulins which tend to have their low points or nadir around 4 hours after the shot. With Lantus, is is more commonly around 6 hours after the shot, with some variability by cat and cycle.
, pretty difficult. I wonder tho how much does the stress of the pokes changes the glucose values? 
I just want him to go back to yellow 
).
Thanks.
I do hope we can get used to them soon. Just not sure how I feel about a lower pre-shot number than the usual.