What should I continue from this point?

[Nyalia]

Perhaps, but GSM is arguably one of the cheapest and easiest to get to 50 (jewel rocks are plentiful and cheap), plus the extra boost from Innovation does also give an extra boost in exp (which would help with the rest of the crafts). This reasoning is obviously not for a master crafter, but it might be a bit more more useful to someone with more limited resources and options.

This is a good point, and incidentally, it's a great argument for getting BB before CS2 (I'm editing my post above with that in mind).

GSM is a wonderful class to have, especially if you want to get into Desynthing.