This is another great example of on of the major things that is really slowing down the UKA advances are now natural barriers, not necessarily Russian troops. The salient moving NW out of Siversk (very bottom right arrow) only has to advance just a few km because to the NE of Lyman is a large lake and then as you follow the lake north is swap/marshland that may or may not be easily passable for armor. The current UKA advance east of Oskil that is splitting to finish the encirclement of Lyman, and then a projected advance to Svatove is currently marked as only extended to the banks of the river feeding the lake NE of Lyman (once again marshlands and can the UKA armor get through to hit Svatove from the south). The advances from Kupiansk and Dvoricha (the 2 northern arrows) are instead following the highway (and most likely advancing on the preprepared positions) and are north of where that river ends.
What is more interesting is that the Lyman pocket, once fully closed, adds a second location that is now inside the 30km firing range of the UKA barrel artillery (the first is the ridge directly west of Svatove on the UKA side of the Oskil river) and so as the Oskil river group works its way across the marsh/river there after closing the Lyman pocket, the artillery units should be able to roll in behind to provide additional fire support and begin softening up Svatove.
Once Svatove falls, the next major defensive line should be on the N/S inline with Misky down the river to Sievierdonetsk, with the added bonus that Svatove is a little more that 30km from Starbolisk, or now would be in conventional artillery range.
That entire front is hanging on by a thread at this point, and slowly more and more people are realizing how quickly this could become a collapse with not a ton of place for the troops to pull back to.
Once again is this poor planning, poor execution in the field by the RU, lack of COC, a lack of troops, or a mixture of all of it by the RU.