I just received last week recently a "new" Curiosity HPC (rev2)
and it includes all the features you are looking for including on-board USB<==> UART converter (no more need for an external Click board or converter cable to do USB<==>UART conversion ;=)
After unpacking it, I discovered that despite having the same reference as the old one ( DM164136 ), there are significant hardware changes on the debugger side....
The debugger chip is now a much more powerful device (ATSAME70 300MHz) which shows up as PKOB4 (enhanced version of old PKOB based on PIC24FJ256GB106 24MHz). If my memory is correct this is the same chip which is inside the Pickit4.
As a result :
It is flashing much much faster
It enumerates both as a debugger tool AND a virtual COM port using a single USB cable
There are 2 pins (UART TX and RX) which can be connected to any pins of the 8 bits target PIC using simple wires.
All this is visible in the users manual
which shows Rev1 and Rev2 schematics at the end.
I have used this UART with PIC18F26K83 this week successfully to "printf" messages on the PC.
For me the most valuable, is the blazing speed of flashing from PKOB4 compared to PKOB...
The issue might be when you order is that you can't be sure to get the new or old one...because they have the same reference. New one came with a full red box while old one was in the black box...