Take Recorder - Viewport Freezing and Performance Degradation When Recording Without Subsequences

Description: In Unreal Engine 5.4, when recording camera movements using the Take Recorder with the "Record Sources Into Sub Sequences" option turned off, significant viewport freezing and performance degradation are observed. This issue affects both simple camera recordings and virtual camera setups using LiveLink data for camera movement. Despite the viewport freeze, recorded takes still capture camera motion accurately, suggesting the issue is isolated to the viewport/Take Recorder during the recording phase. This makes virtual camera recording workflows, particularly those not utilizing subsequences, nearly unusable due to the viewport not updating in real time.

Repro video: [Link Removed]

Steps to Reproduce:

1. Set up a cine camera actor for recording in Unreal Engine 5.4.
2. Open the Take Recorder and ensure "Record Sources Into Sub Sequences" is turned off.
3. Start recording camera movements.
4. Observe the viewport for freezing or performance issues during recording.
5. Stop the recording and review the captured take for camera motion.

Expected Behavior: The viewport remains responsive, and performance does not degrade significantly during recording, regardless of whether "Record Sources Into Sub Sequences" is enabled or disabled.

Actual Behavior: The viewport freezes during recording when "Record Sources Into Sub Sequences" is turned off, although the recorded take captures the intended camera motion. Performance degradation is noted, impacting the usability of the Take Recorder for virtual camera recordings.

Notes:

• Initial investigations suggest the issue may relate to the number of properties/keys being drawn in the sequencer, with performance tanking due to extensive slate redrawing.
• Similar performance drops have been observed when recording two skeletal meshes, further indicating the issue might be tied to the sequencer's handling of properties during recording.
• A workaround involving not drawing the keys during recording has been suggested, akin to a previous solution for audio waveform redraw issues.

[Link Removed]