There is evidence cited here
https://www.files.ethz.ch/isn/25742/report_04.pdf
that in 1990, before the independence of Ukraine on 24 August 1991, the state granted
extended cultural autonomy rights to ethnic minorities.

This was probably the basis for Transcarpathia to have its own time zone, like Europe/Budapest, between 1 July 1990 and 29 Sep 1991.

From 29 Sep 1991 onward  Europe/Uzhgorod and Europe/Kiev are the same.

We still lack newspaper article evidence.

There is strong evidence for a renewed autonomy movement in Transcarpathia with its partly Rusyn population,
at the time of the decay of the Soviet Union in 1990.

The center of this autonomy movement was Uzhgorod / Uzhhorod at the Slovakian border.
See for example https://litopys.org.ua/rizne/magocie.htm

While I have not (yet) found direct evidence of an official local time zone of CET during the period in question, I have found several quotes
that there exists a tradition for parts of the population to use 'Hungarian time' in the region.

This makes Shank's claim again more believable.

Once Ukraine stabilized after gaining full independence, it blocked all such movements in its southwestern province.