In the OTU
1.Empress Wave - This is a factor as it causes the break up of the Zhodani Consulate and causes disruption of electronics and such for centuries to come.. It enters the coreward Imperial sectors in the early 1200's going rimward at light speed. You would need to wait until it leaves Imperial space in OTU. If it exists in Lorenverse, there will be a time of discovery and exploration I think before reconciliation of timeline. At least you have to wait until it passes in OTU.
2.Zhodani Concord - In OTU, the Consulate is disrupted/destroyed of Empress Wave, replaced by the smaller and more manageable Concord. To line up, it has to be broken up in Lorenverse and associated impacts (Vargr/Imperial Landgrab?) or wait for the Consulate to "rise again" in OTU.
3.K'kree - In OTU the Dominate was NOT PERMANENTLY defeated at the Second Battle of Gateway Station in 1247. The 4th Imperium has around 5 years until it becomes a factor of some sort (Out of Darkness p. 133) that some Viral Entity/Charismatic K'kree rises up to start problems again. K'kree space must be disrupted in Lorenverse or cleaned up in OTU
4.Virus - is a part of OTU, with Viral Entities being granted citizenship. OTU needs to have Virus "grow up" or eliminate it. Harder to eliminate as even the "nice" Imperial Virals are not just going to lay down and die. This helps resolve point 3 in part. Or makes reconcilliation that much further in the future. So more likely Lorenverse must introduce Virus at some level at a "nicer" level.
5.Territorial claims - In OTU. the 4th Imperium disavowed ALL claims over the previous Imperiums at its inception (p.66) and its future "plans" include a limited size realm.
6.Vargr and Aslan - are major populations in the Fourth Imperium, so what allows their integration in Lorenverse.
7.The Spinward Marches - as a "Regency" or Imperial Domain whatnot is gone by 1248 in OTU, so what is the cause of break up in Lorenverse? What might happen as reconciliation post-1248 in OTU?
Lorenverse, is a step back. Not having the rebellion, break up of 3I, collapse of the Regency or anything from 1248. The Empress Wave is open for not ruffling the feathers of anyone. Just a distress call. The K'Kree are not driven to destroy anything. Virus does not exist.