I don't really know if this fits in this community, if not just take it down. The map is from the BlackBird group.
Regarding the recent strikes on the Seim river crossings, I've been speculating what Ukraines plans are. Not too long ago, the Ukranian advance around Korenevo slowed a bit. Then they started systematically hitting the Seim river crossings, of which ISW assesses there is only one left.
If the goal was to encircle and trap Russian units, I would assume that Ukraine would make a hard push through Korenevo to the river. As it looks now, it seems like they are leaving a small corridor open. Whether that is due to Russian resistance or Ukrainian planning I have no idea.
This makes me wonder whether they are intentionally leaving a small opening (See: Sun Tzu) to try to make Russian forces low on resources funnel through the opening where they can inflict heavy casualties, or whether they are trying to force the Russians to expend resources trying to prevent being cut off before they close the net.
In any case, I can see Ukraine wanting to secure another major road towards Korenevo that they can use to supply the offensive.
Of course, I don't want anyone to reveal anything that could violate OPSEC, everything I read is based on OSINT. I'm just interested and would like to hear other peoples speculations.
I was speculating in another thread that I believe they are going to push west and take the territory south of the river as Ukraine has destroyed Russia's ability to reliably get supply into the area.
As far as bleeding out extra forces, as you mention, that would certainly be a solid strategy. Ukraine recently destroyed a Russian pontoon bridge to the region. If Russia is determined to keep putting up new bridges, it would certainly be possible for Ukraine to target Russian engineering units, potentially even waiting for a few units to get over the fresh bridge before blowing it, trapping the units on the under-supplied side.