I think understanding YOUR water composition is the utmost importance when treating water. Without that understanding you might as well not treat it at all as you don’t know how to treat it.
With that, you shouldn’t need to lower the pH with acid then add baking soda to raise the pH. You should target a pH with the addition of your grains. The darker the grain the more acidic it is and will therefore drop the pH naturally.
If you don’t need much to treat your water to reduce pH you could also use acidulated malt. Every 1% of the grain bill will drop your mash pH by 0.1 point.