Merge to Panorama stability and performance issues (LR 7.5 classic)

Issue: Lightroom Classic Version: 11.5 [ 202208080927-8a575c91 ]

OS Version Number: Windows 10 - Business Edition
Version: 10.0.19044

Steps to reproduce:

Executing a Photo Merge Pano (after a successful Preview step) with a few large RAW files (Fuji GFX100).

Expected result: As per earlier LR 7.x versions, pano merge will progress in a *fairly* linear way, where extensive periods of time are not spent with almost zero progress for many minutes on end, during this time completely locking up LR and the rest of my apps. FYI: I have a pretty decent spec workstation, 32GB RAM, SSDs, reasonable CPU with clear spare capacity on disks inc. scratch disks, virtual/paging memory.

Actual result: After sometimes initial linear progress on the % processing the merge Lightroom now often hangs and makes interaction with other apps impossible as it hogs the foreground/maximise functionality for significant periods of time. Often I have ended up force closing LR as the merge appears completely stuck.

Further sys info:

Lightroom Classic version: 11.5 [ 202208080927-8a575c91 ]
License: Creative Cloud
Language setting: en
Operating system: Windows 10 - Business Edition
Version: 10.0.19044
Application architecture: x64
System architecture: x64
Logical processor count: 16
Processor speed: 3.7GHz
SqLite Version: 3.36.0
Built-in memory: 32675.3 MB
Real memory available to Lightroom: 32675.3 MB
Real memory used by Lightroom: 16087.5 MB (49.2%)
Virtual memory used by Lightroom: 24902.8 MB
GDI objects count: 814
USER objects count: 2930
Process handles count: 2591
Memory cache size: 0.0MB
Internal Camera Raw version: 14.5 [ 1177 ]
Maximum thread count used by Camera Raw: 5
Camera Raw SIMD optimization: SSE2,AVX,AVX2
Camera Raw virtual memory: 7287MB / 16337MB (44%)
Camera Raw real memory: 7380MB / 32675MB (22%)
System DPI setting: 144 DPI (high DPI mode)
Desktop composition enabled: Yes
Displays: 1) 3840x2160
Input types: Multitouch: No, Integrated touch: No, Integrated pen: No, External touch: No, External pen: No, Keyboard: No

Graphics Processor Info:
DirectX: NVIDIA GeForce RTX 2080 SUPER (31.0.15.1748)