I think the theoretical max is a +21 RoW (+4 from Imp, reforge twice + 15 SoU) which would give you +12 equipment. Combined with Rogue's Enhanced Rings talent, you should be able to get effectively a +37 ring (both rings upgrade each other when worn together) which would give you a 39000% boost.

Just more grass in my experience. Underwhelming.

I think the theoretical max is a +21 RoW (+4 from Imp, reforge twice + 15 SoU) which would give you +12 equipment. Combined with Rogue's Enhanced Rings talent, you should be able to get effectively a +37 ring (both rings upgrade each other when worn together) which would give you a 39000% boost.

For my money, Ring of Arcana is the best use of a maxed out Ring of Wealth. A +19 and a +11 ring boosts glyphs and enchantments by 17300%. This means glyph of Stone or Viscosity eliminates all physical damage, glyph of Thorns deals over a 1000 damage and glyph of Flow gives you movement speed of over 1000 per turn in water. At the same time, Grim weapons execute any non-boss at first hit, Vampyric fully heals at any hit, Projecting gives you 174 range (including around corners) and Shocking deals 2000+ damage in the area of effect (but not to the main target - go after the larvae).

Kinetic is also cool with 4000+ damage stored, but since it doesn't keep building, it only helps you with every other enemy.