Useful new website for genetic modeling, an improved version of Vahaduo:

It looks nicer, works faster, and includes new useful features.

I tested it by modeling Romanians. The first image is from Vahaduo and subsequent images show the same models run through this website's stability calculator.

A robust passing model should have good z-scores (>3) and a low G25 distance fit, but good z-scores are more important than tiny improvements in distance.

A z-score below 1 indicates that a source is adding useless noise. A z-score of 1-2 indicates that the source is absorbing residual ancestry but the signal is weak; it could be a decent but imperfect proxy, competing with other sources, or adding noise. Only keep if it makes historical sense and meaningfully improves the fit. If not, drop.

Moldavians and Transylvanians can be modeled with Thracians, Slavs, and Sarmatians/Scythians only, but Muntenians definitely require an Aegean source. Germanic can be added, but it weakens the model.