To answer the first part.
Is it helpful to weight loss?
No or at least not directly. If you are staying clear of simple sugars, or foods that are quickly broken down to simple sugars then you blood sugar will not rise from food. Checking it will not make any difference. If you are still eating refined sugars, or foods that make simple sugars quickly, then you may want to look at your blood sugar.

However, I would not recommend the latter idea. Any rise in blood sugar is accompanied by a rise in insulin, and a subsequent switching of ketone production, and a reduction of satiety.

For a time I looked at mine, but I was worried about low blood sugar when training, and was curious about how high it would go physiologically in response to exercise.

The best thing you can do to stop the chance of developing type II DM is to stick to this WOE. If checking your sugars helps in that then use them but don't get hung up on the numbers, just carry on with a LCHF diet.