Issues with Onboarding Funnel Analysis Due to Delay in ID Merge Propagation and Real-Time Tracking Challenges

I've been having problems when analyzing onboarding funnels in reports due to the delay in ID merges

It may take up to 24 hours for this mapping to propagate to all other parts of the system. This means that, in some cases, when analyzing a funnel that spans pre-login and post-login behavior in real-time, some may be shown as dropped-off, even though they’ve performed the conversion event.

I wonder if there's a way to flush the merge immidiately or if someone figured out a way to keep the onboarding funnel work properly realtime