Season 14 PTR - Mythic crafting

It seems like crafting new mythics is RNG based mechanic that doesn't feel like an upgrade of item but a chaotic mythic amalgamation. Blizzard, besides what you added in season 14 you should also add a feature that will allow players to upgrade unique item to mythic quality using resplendent sparks. Season which is build around mythics should also make mythic currency valuable.

For example players would have a choice to craft mythics with blessing of RNG, OR when using resplendent sparks in a cube players would upgrade an item to mythic quality with exact same affixes but higher quality - no rng involved. Higher cost but guaranteed satisfaction.

What is your opinion on this?