  We have developed an open-source pipeline for the analysis of
\textit{Spitzer}/IRAC channel 1 and 2 time-series photometry, incorporating
some of the most popular decorrelation methods. We applied this pipeline to new
phase curve observations of ultra-hot Jupiters MASCARA-1b and KELT-16b, and we
performed the first comprehensive reanalysis of 15 phase curves. We find that
MASCARA-1b and KELT-16b have phase offsets of $6^{+11}_{-11}~^{\circ}$W and
$38^{+16}_{-15}~^{\circ}$W, dayside temperatures of $2952^{+100}_{-97}$ K and
$3070^{+160}_{-150}$ K, and nightside temperatures of $1300^{+340}_{-340}$ K
and $1900^{+430}_{-440}$ K, respectively. We confirm a strong correlation
between dayside and irradiation temperatures with a shallower dependency for
nightside temperature. We also find evidence that the normalized phase curve
amplitude (peak-to-trough divided by eclipse depth) is correlated with stellar
effective temperature. In addition, while our different models often retrieve
similar parameters, significant differences occasionally arise between them, as
well as between our preferred model and the literature values. Nevertheless,
our preferred models are consistent with published phase offsets to within
$-8\pm21$ degrees ($-1.6\pm3.2$ sigma), and normalized phase curve amplitudes
are on average reproduced to within $-0.01\pm0.24$ ($-0.1\pm1.6$ sigma).
Finally, we find that BLISS performs best in most cases, but not all; we
therefore recommend future analyses consider numerous detector models to ensure
an optimal fit and to assess model dependencies.
