I would kill for some kind of way in-game to test synths. So many ways they could incorporate this into the actual game and economy too. They could make an actual Crafting Simulator furnishing for the house. Could be a nice level 60 3-star recipe for the crafter who has it all. You would insert Grade 1-4 Crafting Prisms (bought from the housing vendors for about the same as a Clear Prism or something) and the requisite amount of shards/crystals/clusters and it would let you run a test synth for a recipe of that tier. Grade 1 Crafting Prisms would be level 60, Grade 2 would be 1-star, Grade 3 would be 2-star, and Grade 4 would be 3-star.

Or make the next tier of crafting benches come with this functionality. Forgemaster's Bench - 3-star recipe, uses red scrips to make, gives Blacksmiths level 60 and below a bonus to either CP, Craftsmanship or Control (your choice) and lets you test any blacksmith recipe using the requisite crystals and Crafting Prisms.

Or make new beast tribe recipes that work this way - Gnath gives you the parts like the Ixali quests did and you craft whatever Gnathy thing they want made. You can keep requesting more parts to make more things much the same way you can keep getting parts from the Ixali quest NPC's if you fail the synth or lose the mats.

Lots of different ways to go about it.