Putin agrees to resume three-way talks on Ukraine war with Kyiv and Washington, Kremlin says
(www.theglobeandmail.com)
that's all reasonable, but Ukraine hasn't offered to stop attacks during any negotiations, and if Russia was capable of boosting it's defenses, why wouldn't they have done it already. Given Russia's nature, it seems likely that they're doing literally everything that they're capable of and not much is held in reserve.
I mean - i agree with your underlying assumption that Russia is not serious or trustworthy. But if Ukraine never stops attacking the refineries, the the 'negotiations for the purpose of stalling' doesn't work.
I have a lot of faith that Ukraine and their supporters are much, much smarter than the Russians. Russians have excess brutality but not more brain power.