Both are quite fine, you pick what makes sense to you.
Get it to 8dkh first, MG to 1350ppm and CA to 420ppm and get those numbers to “hold” for two months. The higher the Alk, the higher the cost.
Is doesn’t matter nothing if your 8,9,10,11 BUT, it MUST remain absolutely stable, 24-7. Without this stability backbone, nothings going to be happy except pest type crap.
I found it easier to manage water chemistry with a cheap $80 Jabeo DP-4. I buy only premixed product as it doesn’t clog the Doser and is in the same relative concentration every time.
As an example, my Doser adds on every hour, 2ml of Seachem Fusion 2 ALK, and on every half hour 2ml Seachem Fusion 1 CA, 10ml per day Red Sea MG. These amounts are what the system is using and I need to replenish, only what’s used.
That amount of course, different in every system.
All systems have a sweet spot where they prefer to run at. If that number is in, or close to traditional ranges, and holds firm, just keep that number.