Except for Ultimate Traffic 2, which is what I use for AI traffic. As I understand it, UT2 uses FS9 models which will not display in P3D. I might be able to change those models to FSX native, but that would be a lot of work and potentially not possible for all of the AI aircraft in UT2.I gave up on FSX when 64 bit P3D v4+ arrived in 2017 and never looked back.
P3Dv4.5 runs much more smoothly - on the same PC - than FSX and with no more CTDs or OOM.
Plus all my favourite (native) FSX planes, Orbx Global and ADE work fine.
Really a no brainer.