USB2 is not so critical like some (in most cases) older USB3 chips from, e.g., ASMedia. But even ASMedia 3rd party chips became better, but I am missing the long-term experience here.

I am always using cards with FL1100 chips because I have a good long-term experience with it with UFX+, UFX III (USB3) as well as ADI-2 Pro FS R BE (USB2).
Works also well in combination with the StarTech USB3 extenders (also USB2 compatibility given towards the ADI-2 Pro).

Sure is

a) it is still a good idea to isolate a recording interface behind a USB controller of its own. When using ports from your chipset this will work, but in most cases difficult to identify, which ports belong to which internal USB controller in the chipset. Getting a dedicated card makes it easier.

b) do not spoil a precious PCIe socket of your mainboard with a low bandwidth USB2 card. It is much likelier that you won't get one anyway. If you get an additional card, then I would use one which is also best supported for USB3 interfaces. For two reasons: just for the case you might get one and assuming that it will become more difficult to get such a card with FL1100 controller in the future.

Whether this FL1100 chip is a couple of years old doesn't matter. More important is, that it is well-designed and works fully compliant according to the specification for USB transfer modes suitable for audio. Or that the card reacts to interrupts well.

Remember back XIO2200A FW400 chip from Texas Instruments, this chip had issues because he didn't react well to interrupts so that audio packets could become lost. The reason TI labeled this chip as "do not use in new designs". Sadly, many FW400 had been built and sold with this unfortunate chip.

You can also try USB3 cards with ASM chipset. The USB3 PCIe cards with newer ASM chips seem to work much better.
I tried it shortly whether it works with UFX+ and UFX III, yes there were no USB3 transport errors, but I am lacking here the long term experience.

The following cards with ASMedia chips I have in the system, which seem to behave well:

Sonnet Allegro, 1x Fresco Logic FL1100EX), (USB3-4PM-E), PCIe 2.0 x4
For connecting UFX III

StarTech dual Port USB 3.2 Karte - 10 Gbit/s per Port - 2x USB-A, PCIe 3.0 x2, ASM3142 (PEXUSB312A3)
With UASP support, using this for my external USB3 disks with 10TB capacity.

Sonnet Allegro Pro, 2x ASM 3142 (USB3-PRO-4P10-E), PCIe 2.0 x4
Connecting here several USB devices, ADI-2 Pro FS R BE (for remote control), USB3 switcher and other stuff
A little expensive through because it has two USB3 controller on board.

This card I took out to proactively avoid any potential of coil whine, which I had with the card below
StarTech dual Port USB 3.1 Karte - 10 Gbit/s per Port - 2x USB-A - PCIe 2.0 x4, ASM2142 (PEXUSB311A2)

What worked in the past, but not available anymore. I had to buy a used card because one port became defect.
And both cards became at the end coil whine ... the damaged and a used card.
Sonnet Allegro Pro USB3.0 PCIe, 4x Fresco Logic 1100

ramses, Thanks for you time this is very helpful.

This is helpful, curious what motherboard/cpu combo are you using.

I'll likely be building/buying a new system in the coming months and still undecided on what direction i'm going.