I have only ever perused Twinmotion, it does nothing for me.
At the time I was running with a Ryzen 9 3950x CPU and a 8GB Gigabyte AMD RX 5700XT GC. 32 GB GSkill Ram and a 850 Gold PSU. Powering a 4k Monitor.
None of which supports Hardware Raytracing, which to be frank, I could not see the real benefits of, unless you are a Movie Maker that wants UHD (4k) resolutions in realtime lighting.
It sounds like Twinmotions are excluding around 40+% of the PC markets. Movies can be shot in Pre-rendered scenes using Software Ray Tracing which is baked along with all lighting.
The only part I can give an answer to is how my specific setup copes with Unreal, Lumen, Niagara, Nanites etc. Scoring the system alongside a lesser spec system running a AMD 570XT GC with only 4GB ram onboard and 16GB of generic ram, using a 2K monitor, only saw a few frame drops.
Both systems running up to date Win 10 OS and from NVMe drives of around 500mb/sec speeds.
I have made Movies in other Editors other than Unreal, without issue, filming scenes with Millions of Particles exploding on screen with any frame drops. As well as the physics of moving foliage and objects.
I used to run nVidia GC’s and they were excellent, but when coupled with a AMD CPU and a AMD South and North Bridge IC’s on an AMD designated MB, along with Matched GSKILL Ram chips that are for the AMD Ryzen CPU you are using… It is hard to ignore the benefits.
However, none of this is relevant if you are fixed on using Twinmotion with its prefix of Hardware raytracing. Personally, I refuse to pay the increases for a Hardware Raytraced AMD GC nor could I justify it for my needs. The research I did before deciding on what was good for my needs, was that the results using hardware ray tracing, was not discernible to the naked eye.
The Unreal editor has Camera Cranes, motion editors in realtime, and all you need to produce Movies, without leaving the Editor. You do not need Hardware raytracing either.