This is the example code in SDK for i.MX RT 1015 clock configuration and the DCDC voltage regulator setting for 500MHz operation:
/* Setting the VDD_SOC to 1.5V. It is necessary to config AHB to 500Mhz. */
DCDC->REG3 = (DCDC->REG3 & (~DCDC_REG3_TRG_MASK)) | DCDC_REG3_TRG(0x12);
The value DCDC_REG3_TRG(0x12) is for 1.25V and not for 1.5V
I believe the comment is incorrect since the specification gives 1.15..1.3 for overdrive conditions in Run mode.