why Plotly.react() is as slow as Plotly.newPlot()? updating single trace of many

Hi, I am trying to redraw only single trace in a plot of many traces (biophysical data). I tried to follow instructions in react-plotly and plotlyjs documentation:
https://plotly.com/javascript/plotlyjs-function-reference/#plotlyreact
Plot is updated but I don't see any performance improvement if I change only single element of data or all data elements:
Here is MWE in codepen
Briefly, I generated sample data 100 traces of 10000 points and changing only first trace with:

  data[0].x =  [...Array(10).keys()].map( c=> c/10) //change only first trace
  data[0].y =  [...Array(10).keys()].map( c=> Math.random())
  Plotly.react('myDiv', data, layout);

Drawing plot containing single trace takes just a split of second, but if I had already drawn many traces and I want to redraw only single trace, it takes same time as to redraw all traces (few seconds).
Am I doing something wrong?

Inizia con il MWE CodePen collegato e confronta Plotly.react() con Plotly.newPlot() usando i dati indicati con 100 tracce e 10.000 punti. Leggi la documentazione collegata di Plotly.react e segui il percorso di aggiornamento nel repository; l'issue non indica alcun file sorgente né alcun test. Il lavoro sarà completato quando saranno identificate le cause dei tempi comparabili e sarà definita l'ottimizzazione o la modifica della documentazione prevista.