We've had a number of acrocats follow TR as written, meaning reductions under 50. One exception is that I'm not fond of treating acros as long term diabetics (diabetic more than 1 year), and forcing them to go under 40 for a reduction. What is really important is to Know Thy Cat, and what works for him/her. I have seen some caregivers of acros use the guidelines for three times between 40 and 50 for a reduction. I tried it, just once, and found out it wasn't a good guideline for Neko. She pretty much always held her reductions.
If an acrocat has been treated (cabergoline, SRT, or hypophysectomy), then a more cautious approach is needed and reductions earned at higher values, if the cat is having a series of reduction one after another. For example, sometimes people giving cabergoline or having done SRT will use reduction points of 70.
For cats that have not been treated, the acro tumour can still pulse, meaning reduce or increase, with a corresponding change in amount of insulin needed. It could be that Micio is in that phase right now.
So, if you find yourself having to quickly do several reductions in a row, you can chose to raise the reduction point a bit - temporarily. Then put it back to 50 when the series of reductions has stopped or slowed. But you also have to keep in mind the action of the larger depot. It can influence 4-6 cycles after a reduction, possibly more in larger doses. I would expect to see somewhat lower numbers for at least 3-4 cycles after a reduction, and wouldn't lower the dose then, unless going under 50. If you reduce too fast, you find yourself seeing higher numbers and having to go back up in dose.
To answer the question about whether 50's are OK, the answer is "it depends". There were times when I let Neko stay on a dose seeing the 50's. But if SRT was kicking in, I didn't and preferred nadirs in the 70's. You will find you have to experiment with Micio, and find out what works for him. If he holds reductions when he goes below 60 (as an example), then maybe that's a good reduction point for him. But do keep in mind you may see the 50's for a few cycles after a reduction because of the larger depot.
Note for any lurkers, the suggestion above is only for Simone and Micio.