Which Hyperhub should I buy for an iPad Pro 5th gen?

You may find that a USB-C hub that connects via a short “stub” cable will be both less troublesome and more flexible for your needs. Hubs that connect flush to the iPad are generally impossible to use if your iPad uses a fitted case for protection. Consider also that cable connected USB hubs can be more readily used with other computers - whereas a hub designed to connect directly to an iPad might not be easily usable (if at all) with other computers.

Many have found that due to their size, larger iPads (in particular the 12.9” iPad Pro) are more prone to damage - and significantly benefit from the additional physical protection and support afforded by a hard-backed case (such as Otterbox or STM Dux series cases - both of which feature a polycarbonate back and TPU surround). Hubs that connect directly to iPad, intended to sit flush against the iPad, cannot be used in these applications. Whether you use a case now, or in the future, a cable-connected hub retains flexibility in being usable either with or without an iPad case.

Likewise, if you mount your iPad on a stand/easel, the weight of the USB Hub and attached cables places stress on the iPad’s USB-C port - and can de-stabilise the mounted iPad. Using a cable-connected Hub removes this issue - and reduces stress on both the iPad USB-C port and the iPad chassis.

You may also find that you have a greater choice if you choose a cable-connected hub in preference to a direct-connect type. Now, armed with this knowledge, you can make a more informed choice for your needs.

As to the technical specifications of the USB-C hub itself, you would be wise to choose a hub with a USB-C PD (Power Delivery) port to which you can connect your iPad Power Adapter. This port provides pass-through power, to both charge the iPad and power the hub itself. All hubs requires power to operate - and will consume significantly more of your iPad battery power when connected to your iPad; USB accessories, in particular USB storage devices, also consume power. The ability to simultaneously connecting your iPad Power Adapter provides greater flexibility in being able to use an external power source when available, or battery power alone for portability.

You would also be well advised to select a hub that incorporates both USB Type-A and additional downstream USB-C ports - as this will provide flexibility in being able to connect both types of USB connections to your iPad. Other ports to look for, which may or may not have relevance to your needs, are HDMI, VGA, Ethernet LAN, SD and microSD card-reader slots.

Surprisingly few hubs incorporate a 3.5mm headphone jack - and of those that do, many will be found to create some difficulties with audio routing when connected to headphones. For hubs that don’t provide a 3.5mm jack, but feature a downstream USB-C port in addition to the USB-C PD (charging) port, it is trivial to add a 3.5mm jack using Apple’s tiny USB-C to 3.5mm Headphone adapter:

https://store.apple.com/uk/xc/product/MU7E2ZM/A

Perhaps consider Kingston, Anker, Hyperdrive and Satechi - although there are many others from which to choose. A Google Search for USB-C Hubs compatible with iPad will find a number of articles and recommendations. 

Speaking of personal experience, the Kingston Nucleum has proven itself to be particularly flexible for connection of high power USB storage devices - featuring twin USB3.1 Type-A, downstream USB-C and SD/microSD card slots, HDMI, plus a power pass-through USB-C port that can accept +45W from a suitable USB power source.

If looking for an HDMI Adapter, be aware that few USB-C HDMI adapters/hubs support HDCP 2.0 - absence of which will inhibit the ability to output copy-protected HD media content from iPad to a connected monitor/TV over an HDMI connection. 

The Apple USB-C Digital AV Multiport Adapter does support HDCP 2.0, but lacks the flexibility of many USB-C hubs:

https://store.apple.com/uk/xc/product/MUF82ZM/A

Note also that most iPad models that feature USB-C also support DisplayPort Alternate Mode over USB-C. This protocol allows direct connection, with an appropriate Thunderbolt cable, to a monitor that supports DisplayPort - removing the need for HDMI.

Here is a link to Macworld published Nov 2021 which recommends a few USB C Hubs which are capable of meeting your requirements and more if needed. https://www.macworld.com/article/349019/the-best-usb-c-hubs-for-the-ipad-pro-and-ipad-air.html

Dear Barrelhoop, you are correct, there are so many available it does make it difficult and it generally comes down to ports available, compatibility with your iPad and fit for purpose. Apple also provides adapters for various uses. I preferred to have my Hub plug into my iPad (same as yours) with no additional cables (small and compact for portability) whereas others prefer to have a desk mounted Hub. Either way you could check out Tech Youtubers (GregsGadgets, Mrwhosetheboss, Fernando Silva, 9to5Mac, Zollotech, Max Tech...) in YouTube which may help you decide.

I’m delighted that the additional insight was helpful to you. I’m sure that many will find a report of your experience to be helpful when seeking a similar solution.

It’s great to hear that you have a solution that works for you. Others that come across this thread will no doubt find your report to be helpful in informing their own choice.