performance tips for computations on an ESP32

BTW, with cached globals like that even not compiled is like 2x faster than before, just changed "compiled" strings and

384.521484375 16.87622070312 866.69921875
385.55908203125 15.80810546875 869.32373046875
385.34545898437 15.31982421875 868.83544921875
385.498046875 15.869140625 868.62182617187
384.42993164062 16.14379882812 868.37768554687
386.56616210937 15.07568359375 870.02563476562
385.31494140625 15.28930664062 869.53735351562