Actually, looking back at this, are we sure the Spanish Empire had a larger GDP than Japan in the 17th Century? Yes, they’re colonial empire was massive, but most lived in extreme poverty (extreme even by pre-modern standards); and the Tokugawa actually had a larger population circa 1700 than the Spanish Empire did.
On that subject, it looks to be very possible for Japan to have a larger economy than the Tsardom of Russia TTL, considering they had about twice as large a population and only fell slightly behind during OTL’s 17th Century. I can actually see a scenario TTL where at the start of the 18th Century, you have the big three economies of the world -- the Qing, the Mughal, and the Ottomans -- and the next two largest economies are the French and Japanese, poised to surpass the latter.
Then, depending on how the 18th Century as a whole goes for them, Japan could be one of the major economies just behind China and India going into the 19th Century (OTL, powers along the lines of Britain, France, and Russia).