  The minimum variation timescale (MVT) and spectral lag of hundreds of X-ray
bursts (XRBs) from soft gamma-ray repeater (SGR) J1935+2154 were analyzed in
detail for the first time in our recent work, which are important probes for
studying the physical mechanism and radiation region. In this work, we
investigate their differential and cumulative distributions carefully and find
that they follow power-law models. Besides, the distributions of fluctuations
in both parameters follow the Tsallis $q$-Gaussian distributions and the $q$
values are consistent for different scale intervals. Therefore, these results
indicate that both parameters are scale-invariant, which provides new
parameters for the study of self-organized criticality systems. Interestingly,
we find that the $q$ values for MVT and spectral lag are similar with duration
and fluence, respectively.
