I am considering Yandex Metrica over Google Analytics due to Yandex offering session recordings and heatmaps as a default.
However, I'm worried that the load time will increase and thus hurt the organic rankings.
The tracking script loads asynchronically. So first a page loads in the browser, renders, then script starts. just add it at the bottom above </body>
besides, just test with and without tracking on gtmetrix, and webpagetest