I think that most likely the sleepless effect will go away as the enzymes adjust so the best thing to do might be to lower the dose and take it only twice a day for a while with the last dose being at least 6 hours from when you want to sleep for the night.
After a person is adjusted to a particular dose they could gradually raise the dose and when they don't have trouble sleeping with a three gram dose twice a day they could start adding in an evening dose making that dose as small as the other ones were at first and building up.
When the body is really low in something used in an enzyme reaction, the body tries to compensate by making large amounts of that enzyme. If the person takes that something as a supplement then suddenly they have too much of the product of the enzyme and probably other things too down the line, and the person has unwanted side effects until the body has time to lower the amounts of the enzymes. This happens a lot with people with ME/CFS because it appears that they are very low on a lot of things.
This is why it is so important to start low and build up, and to build up on the B vitamins together. But I think it would be a mistake to take it to mean that you can never take a larger amount of some vitamin, it just means you have to go slow in building up the amount. Some people might have to go very slowly.
