BE ADVISED! VIDA detects any module replacement or addition!

[IMAY2023]

I cannot comment on Android base OTA updates but SPA sensus has no problem. 
If you ever replace your IHU with a used one, then downloading new apps and updating maps and apps online won't be possible. But it is still possible to update the maps via USB. 
VOLVO checks the IHU part number and installed & available software and compares it to the VIN. If the IHU HW number does not match to VOLVO db, it won't let you download any software.

[glennda5id]

My SWM (Steering wheel module) is on the fritz and needs to be replaced. I would also like to add heat which requires a different SWM part number.

If I purchase a used SWM am I going to run into these issues? Is it better just to purchase new and load the software with VIDA?

[IMAY2023]

You can buy a used SWM with heated one and replace the steering wheel too. You might need to wire the positive and and ground though (Some builds are not pre-wired).
Then you can enable the heated steering wheel. However, you most likely will need to recalibrate the SWM for that, you will need VIDA. 

Even you wouldn't need to recalibrate, next time you cannot the VIDA after replacing the SWM, VIDA will force you to reload SWM software before installing total upgrade. 
You don't need to perform total upgrade at all. Your car will continue to operate as it was before and many service centers don't even connect the VIDA and upgrade during periodic service although it's part of the regular maintenance officially. 

If you buy a brand new SWM, you will need VIDA to reload it right after the installation.  You can also add heated steering wheel officially. The software reload costs are exactly the same regardless if SWM is a used one or not.  

So, basically it's up to you.

[glennda5id]

You can buy a used SWM with heated one and replace the steering wheel too. You might need to wire the positive and and ground though (Some builds are not pre-wired).
Then you can enable the heated steering wheel. However, you most likely will need to recalibrate the SWM for that, you will need VIDA. 

When you say recalibrate the SWM are you just referring to setting the config in CEM which can be done "unofficially" via Orbit or are you talking about some sort of other calibration.

[IMAY2023]

No, the SWM has steering wheel position sensor inside.  There is a SWM calibration routine with specific instructions and steps in VIDA. 
In most cases when replacing the SWM that routine is needed to be run for calibration.  In some cases if you are really lucky, the used or new part would be in the dead center and installed on the dead center.