https://www.gaiam.com/blogs/di ...
Published by Suresh Kumar.S
https://www.gaiam.com/blogs/discover/how-to-increase-the-alkalinity-of-your-water
The above might partially answer your question.
TDS could be higher,without problem.
But mineral water has defined parameters,and modified water is just bottled water,and may not be possibly qualified as mineral water. Moreover,in the case of artificial water or process water from RO,it is advised to add vital minerals.