Advance = 40.39km2
Over the span of a week with mounting Russian pressure on western Kupyansk and renewed attacks to the east starting to take some important defences (I believe by the Russian 1st or 153rd tank regiment), Ukraine was forced to withdraw back into Petropavlivka to concentrate their forces. This allowed the Russians to turn their important, smaller trench captures into a significant advance, taking control over a large area of fields, treelines and trenches on the east side of the pocket. It is unclear whether they were able to move into Petropavlivka at this time, as whilst some sources say they established a foothold, others say they are still just on the outskirts.
Regardless, this does shrink the Kupyansk pocket quite a bit and put Russian troops (particularly drone crews) much closer to the key strongholds and supply routes in and out of the pocket. For now Ukraine is holding with the lines being shortened, but if Russia can push into and take Petropavlivka, or replicate this advance further to the south, Ukraine’s positions in the remaining part of the pocket will become untenable.