FCPX AV OUT Monitoring: can/should I calibrate & profile?

Hello. I have been doing medium-level color correction for years, within FCPX. Recently I bought the UltraStudio Monitor 3G and jumped into learning DaVinci Resolve and have been loving it, but my mac is just too slow for serious work with that software. FCPX is speedier, so I need to keep using it until I upgrade my mac.
In Resolve (16) I configured the AV output, calibrated and profiled the monitor using the software interface with DisplayCal3, which works wonderfully with Resolve. So I believe Resolve is giving me a trustworthy output via UltraStudio Monitor 3G, but my mac is too slow for Resolve as mentioned.
So back in FCPX, I know I can use the AV OUT option, but I do not know if I can (or need to) calibrate and profile for that sort of output (calibrating and profiling the 2nd monitor is easy, but that would mean not using the UltraStudio Monitor 3G.
Should I just reset my DELL monitor to standard settings and trust what FCPX and Monitor 3G are sending it? Or is there a way to calibrate and profile FCPX's AV OUT?
Many thanks!

Card should be sending ‘untouched video data’- this is the whole idea behind dedicated monitoring.
You should always calibrate monitor. Depending where calibration lives (software/3rd party box in the chain/monitor) it can compensate for any chain problems or not.

If you for example calibrated in Resolve then as far as I know this compensated for whole chain as patches are coming from Resolve level.
Sometimes you calibrate from monitor level itself and then this only affects accuracy at monitor level.
With BM card signal should not be altered in any way so such a calibration should work with any tool which uses dedicated card ( you should verify it for possible bugs though).

In your case safest is to start from the scratch.

Have you tried using the LUT generated by Resolve in FCP? If you can achieve parity the LUT should respond similarly. Currently (subject to change without notice) the 709-A ICC output Color Profile is properly inverting the QT gamma/gamut.

Good Luck

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Thanks for the replies, Andrew and Howard.
A lot of this is greek to me, and while I am learning and willing to learn, constantly, I many a times feel over my head in these color calibration and profiling topics.

I'll definitely try the 709-A ICC output Color Profile. If I do that, should I set my DELL UP2516D's color setting to Color Space: REC 709, after resetting factory defaults?

How would I use Resolve's LUT in FCPX? I don't think there is a place to set a LUT for the AV OUT, that's my issue, in fact. If you know somehow (or perhaps both are using the same LUT generated by DaVinci? I should do some experimenting and observing with levels and such, although I lack the tools and know-how). Maybe take a picture of the screen with my professional camera, and check if both AV OUTs give me the same picture.
I'll also look into the solutions and paths to follow which you two have suggested, many thanks for the replies!
I just upgraded to Reoslve 17, so I know now there has been improvements in the whole Resolbve-Quicktime-VLC-browser gamma and color shifts which also have been giving me professional-existential chills.