The crafting log is a very viable way of leveling crafters up, using Leves as a supplement rather than a main exp source.

That said, I really do not expect that any 30% bonus is going to make much of a difference. When crafting, one of the things you want to do is add Quality. Quality added during the crafting (IE - this excludes Quality added from using HQ materials) adds to the exp bonus you get at the very end. Not counting Rested, Food, or anything else, that bonus can reach 300%, if you get to 100% Qualioty and use absolutely no HQ materials.

Take all crafting classes to 15 (unlikely to approach that 100% Quality, so the 30% bonus would help here, somewhat). That gets you a solid base of cross class skills. Make any gear you need, then start taking them higher. With level-appropriate HQ gear, and intelligent use of those cross class skills, starting in the lower-mid 20's you will be able to fairly reliably HQ any 70 or 80 Durability craft even with entirely NQ materials (a state that lasts up until you start trying 50+ or 50*'d recipes). 40 Durability recipes would be harder, of course.

Once you hit 15, I'd strongly consider dropping the exp bonus gear for gear with stats, simply because the exp bonus you'll get from adding Quality will far outstrip the exp bonus you get from that non-crafting gear. If, that is, you don't go for stat gear at level 5 (the level you can start adding that Quality).