I think you run into calibration problems with the Public Lab spectrometers. For accurate CCT and CRI numbers, the wavelength scale must be correct within the nanometer over the whole range, and the power levels for each wavelength must be correctly calibrated. It produces recognisable spectra that can be very insightful but can not produce the finetuned numbers needed to evaluate white light sources.
Have you considered a rental? At least here in the US you can rent a Sekonic C-800 for $19/day from lensrentals.com. Try Googling “Rent Sekonic C-800” and see what’s available in Asia.