It's actually quite simple. The clear one is probably fine to use at night but Linlock's lawyers have got involved so there is now the legal disclaimer so beloved these days.
The problem now becomes do you ride at night if Pinlock have said dont. If you are risk averse, given Pinlock's position, don't use one - you will need to buy another spare visor or take the pin lock out to ride home. If you take the point of view that the police won't give damn as long as you were wearing a clear pinlock with the aim of decreasing fogging and increasing visibity then go ahead.
