I think given your goal, it's a good choice of a method.
You can also go a water column dosing method without soil.
This might be more along with some LFS's feelings, but both this and Soil both work very well.
A combination of water column and sediment is what I often suggest, this way you get longer life out of each, this is perhaps more critical as you increase rates of growth typical with CO2 enriched systems, but it works well in any planted tank also. A good fish load can suffice as water column dosing also in a non CO2 soil tank.
Many folks unfamiliar and obviously.....never having mastered the method, may attempt to suggest something else, or tell of their horrors/failures..........
But there are many here that have long term success and little failure.
You could also try the mineralization process or worm castings as alternatives of a DSM to also pre mineralize the sediments, all these still work nicely and might placate and resolve some of the issues that this LFS person has/had.
Many move their plants around too much or do water changes/too many etc.......over stock the tank or under stock the plants. Those are some of the main issues, others: too much light, wrong plant species chosen, lack of patience.
It is the method for your goal I think.