Since the Elite Channel Shop's scrolls are mainly used to scroll hearts, I think that the addition of a Scroll for Soul Shooter for ATT 100% would be fair.
Main reason being:
To get the best stats for your heart, people tend to use scrolls that give +3 main stat & +5 weapon attack. The current scrolls in the Elite Channel Shop has scrolls that give +3 STR/INT/LUK & +5 weapon attack but has no scrolls that give +3 DEX & +5 weapon attack. The current scrolls for DEX classes only give +1 DEX & +5 weapon attack.
Many people might argue that this is unnecessary since there are 10% scrolls available that can be used to scroll hearts (NOTE: hearts are generally scrolled with 100% scrolls that are exchanged with time coins or 10% scrolls + Vega's Spell). However, Vega's Spell cannot work on soul shooter scrolls and they are the only scrolls that give +3 DEX & +5 weapon attack. Furthermore, I've spent around 12 hours only to farm ~25 Scroll for Soul Shooter for ATT 10% scrolls with 690% drop rate.
I do think that this is unfair for the DEX classes that are working towards their end game heart as 22 DEX makes a great difference in the end game. Having the need to spend more time to farm 10% scrolls that have a lower pass rate and do not work with Vega's Spell as compared to other classes is not justifiable. Therefore, I hope that the addition of a Scroll for Soul Shooter for ATT 100% would balance out the discrepancy of the scrolls in the Elite Channel Shop.
1) No scrolls in the Elite Channel Shop with +3 DEX & +5 weapon attack
2) 10% scrolls with +3 DEX & +5 weapon attack do not work with Vega's Spell
3) Extremely time consuming to even farm the 10% scrolls, even then the pass rate is low
4) Unfair as it is more time consuming for DEX classes to scroll hearts