From my experience, it is not necessary. When I was lucky, Sahiya made me some good stuff before I fulfilled most of these conditions (late Act 2/early Act 3). Completed her quests ASAP. Also the post doesn't include any info about town upgrades and workshop upgrades - but I had the feeling artisans in upgraded towns brought better equipment on average - granted I don't have a good sample to back this up. I did upgrade Sahiya's workshop ASAP.
Anyway, if the date is fully accurate, you can try with early Relations, but forget about Economy VIII for now - you can only reach VI before Coronation. Another reason Act V is so critical for Artisan development: Coronation 2 Tiers, Kingdom stats above VI unlocked, Regional Upgrades unlocked.
Generally forget about masterpieces and top-tier items before that (but there's some good stuff below top-tier also, like in Sahiya's case Serpent Prince fauchard or Oppressor bastard sword).
Also another decent reason to go Hour of Rage first in Act IV, to have to Coronation event ASAP.