I have been keeping his numbers low by feeding only LOW carb wet food and limiting his feedings to twice a day.
So great that he's in remission, my George is too. You don't need to worry about that 50 if he's not had insulin. We've had cats report numbers below 50 intermittently when in remission. So you don't need to dole out the HC.
What I would say is that you might want to feed small meals regularly through the day as this is generally thought to be easier on the pancreas, and can help level his BG up over the course of the day.
That 157 before food is a little high for a cat in remission, but the fact he came down 4 hours later tells us that the food stimulated his pancreas to produce insulin and dropped him down to 50, which is great.
In a perfect world, on a human meter you would want to see his range between 50-80 with the occasional reading over 80 but below 120 being normal.
I think that if you took the same quantity of food you are giving him now, give him two main meals at the usual time and then divide the rest of the food up and dole it out as snacks regularly during the day, you might find that those BG's stay more level, and that would put less of a strain on a pancreas that although working well is still delicate.
As an example with George I feed him.
3 ounces at what used to be his amps/pmps (8am/8pm)
then he gets a teaspoon at 3 hourly intervals in between. (you could do 4 hourly intervals if you prefer, but as George has early ckd, I am trying to avoid him getting problems with acid tummy and foamy puke which can occur if he goes too long without eating)
ECID so don't worry if you get readings a wee bit higher than the range I quoted above, George runs between 80-100 usually, and FWIW when he does give me that occasional reading in the morning of 120, it's usually because he's been a lazy kitty and not got up to get his night time snacks

(which are dispensed by his autofeeder, which is invaluable if you are going to dole out regular snacks)