  In 2022 we carried out an upgrade of the speckle polarimeter (SPP) -- the
facility instrument of the 2.5-m telescope of the Caucasian Observatory of the
SAI MSU. During the overhaul, CMOS Hamamatsu ORCA-Quest qCMOS C15550-20UP was
installed as the main detector, some drawback of the previous version of the
instrument were eliminated. In this paper, we present a description of the
instrument, as well as study some features of the CMOS detector and ways to
take them into account in speckle interferometric processing. Quantitative
comparison of CMOS and EMCCD in the context of speckle interferometry is
performed using numerical simulation of the detection process. Speckle
interferometric observations of 25 young variable stars are given as an example
of astronomical result. It was found that BM And is a binary system with a
separation of 273 mas. The variability of the system is dominated by the
brightness variations of the main component. A binary system was also found in
NSV 16694 (TYC 120-876-1). The separation of this system is 202 mas.
