Will DUCCS (Mac) support 64bit on macOS 10.15 Catalina?

Are you asking a general question OR testing a specific Dell monitor model in Apple OS-X Catalina? If testing a specific Dell monitor model in Apple OS-X Catalina, click my name and send me its service tag number via a Private Message.

The latest Apple OS-X DUCCS that I know of, version 1.6.2 for the UP2718Q, does not specify 32-bit or 64-bit. It simply states, "Apple Mac OS". If you see a newer DUCCS version, give me the link. You should also post the question on the Apple Forum to get their thoughts.

Chris, DUCCS is a customized version of i1Profiler and as i1Profiler does, it bundles Xrite services for measurement devices.

AFAIK all i1Profiler versions before v3.1.1 (maybe 3.1) did not support 64bit, hence all current DUCCS versions for macOS do not support it.
i1Profiler v3.0+ was released about 1 month ago and 3.1.1 is just 1 week old:

https://xritephoto.com/ph_product_overview.aspx?ID=1454&Action=Support&SoftwareID=2107

MacOS users will need a DUCCS update if the want to use 10.15 and Windows users will neeed a DUCCS update too if they want to use i1DisplayPro PLUS or i1Pro3 PLUS devices.

Dell UP3216Q monitor is still sold with Mac monitor calibration support stated. However this software is still 32 bit and Catalina is out. Will Dell provide and update and when or do I need to dump my Dell monitor (I need calibration support!)?

Simple question! What is the answer from Dell?

I have the same question/problem (with DELL UP2516D).

It seems they have no answers for us.

Fine...

The latest DUUCS was released in 2017 and is a 32 bit application. Hence it will not run on Mac os catalina. Does Dell have any plans to upgrade the application to a 64-bit version?  If not, what calibration software do you suggest we use?  People who buy Dell’s high-end monitors need colors to be accurate and seeing as the manufactured date in my 2 UP2718q monitors is 2019, it is clear that dell has left software calibration software idle for two years +. We need DUUCS to be updated to a 64 bit app. 

Well, it seems that Dell does not care for their Mac customers anymore.

So, obviously I will have to look for monitor alternatives soon...

If you wish to use Catalina, you need another computer (an old one will work) with 32bit Mac or MS Windows 7+. Install DUCCS there and calibrate. Then copy resulting ICMs to your Catalina Mac and assign them to your display. As always each time you change from one OSD preset to another you need to change display profile.

In Catalina you can use DisplayCAL to validate calibration & profile, or to use GPU calibration for "custom color" mode or other presets.
As in any other display or other calibration software, GPU calibration does not perform gamut emulation, just white, grey and gamma.
You can "correct" CAL1 and CAL2 as your previous calibrations age (whitepoint, grey neutrality issues) using GPU calibration with DisplayCAL untill there is a fix for DUCCS and 64bit macos

I give up. No answer from Dell whatsoever. They just asked for my "Service Tag Number" - whatever that helps - and then silence... MacOS support obviously is history!

I'll replace the monitor with a non-Dell soon! Dell is off my list now for new Mac related devices!

As interim solution, I'll use xrite's 64-bit App, even if this App has no access to the hardware LUT of the monitor.

"As interim solution, I'll use xrite's 64-bit App, even if this App has no access to the hardware LUT of the monitor."

Very BAD idea. If you renounce HW calibration, go for DisplayCAL, don't waste time with i1Profiler.

"I'll replace the monitor with a non-Dell soon! Dell is off my list now for new Mac related devices!"

Don't get lost with bad quality devices like Benq, Viewsonic & company, same SW issues plus HW issues (color uniformity). Go for premium: Eizo.