RE: What are boost tabs???
Da,
Boost tabs were, if I remember correctly,only used on some experimental fighters and some racers (primary on elevator surfaces) just before hydraulic assist became the norm. Hughes did some of the first hydraulic assist systems, and it may even be some of his earlier stuff were boost tabs were used. That is basically the era you'd find any mention of it (end of the "Golden Age"???) just before or near the beginning of WWI.