Valve may have the solution for tracking. Just need a reference design then like the Vive tracking puck (might be able to use) could add laser Tracking to any headset & use Valve base stations.
The 4k yeah unfortunately it seems we are stuck til they finish up the 5k/8k unfortunately.
If I had to guess maybe sometime late q2 or early q3 we might see 4k improvements.
I'd prefer to be wrong though & see something sooner with things like shudder timing adjustments to let us try & tweak performance/quality issues.