Union Alpha reportedly matches DeepSeek 4.1 Flash’s building performance with one-tenth the tokens

EnactraAI says Union Alpha, which it describes as a stealth model, matches DeepSeek 4.1 Flash’s building performance using one-tenth the tokens. Its BuildingBench benchmark compares coding agents on turning real-world images into coherent 3D buildings and assesses the cost.

EnactraAI also reports that GPT‑6 Astra achieved the highest score in its comparison at about 80% lower cost than Fable 5.1. It describes DeepSeek V4.1 Flash’s quality as strong, with a median model cost of $2.31 per building.