I just found this very interesting change that sneaked in one of the patches in BDO.
According to reddit user - Equalness , tests show that SKILL POINT buffs are effecting Skill points gained from SEASONAL SECRET BOOK OF MISTY BREEZE that adventurers get after completion of mainquestline in BDO. The difference in SP attained between buffed and unbuffed
This wasnt the case before.
Link to his very detailed post and explaination - SP buff test by Equalness