The Berkeley SETI Campaign already looked at this, and rates it a Zero to One (None to Insignificant) on a Ten-point scale:
https://seti.berkeley.edu/bl_sdss_seti_2016.pdf
The one in 10,000 objects with unusual spectra seen by Borra and Trottier are certainly worthy of additional study. However, extraordinary claims require extraordinary evidence. It is too early to unequivocally attribute these purported signals to the activities of extraterrestrial civilizations. Internationally agreed-upon protocols for searches for evidence of advanced life beyond Earth (SETI) require candidates to be confirmed by independent groups using their own telescopes, and for all natural explanations to be exhausted before invoking extraterrestrial agents as an explanation. Careful work must be undertaken to determine false positive rates, to rule out natural and instrumental explanations, and most importantly, to confirm detections using two or more independent telescopes.
Peaks in Fourier analysis of stellar spectra, such as those discussed by Borra and Trottier, can be caused by instrumental optics or introduced during data reduction. Data artifacts, fringing, and inconsistencies in the manufacture of detectors are known to users of high resolution spectrographs to cause minute patterns to appear in the resulting spectra. The movement of the telescope, variations in observing conditions, and the process of wavelength calibration can easily introduce undesired signals at levels that are only barely detectable. It is therefore important to check the claimed signal using a different telescope and instrument.
Nevertheless, they've put a few of the Borra / Trottier candidate stars on a "watch list", and it will be interesting to see if any independent measurements show anything out of the ordinary.