A quirk that I have found with the Lightroom versions I have used [LR3 through Classic'19 at time of writing] is that they've been designed to 'play nice' with other programs by not willingly sucking up every last resource they can get their hands on.
Instead they will use a moderate resource level to avoid bogging the system down entirely and preventing ...
Here's my photography-centric answer. How often do you need to do this? Pretty much just once for the full collection. Maybe the equivalent once every few years. At 10 seconds an image, this is going to be done in under ten days.
So, just let it go and worry about something else for ten days.
I know this goes against the generally-admirable instinct to do ...
(Near) IR pass filters are everywhere. For photographic filters, try searching for "IR 720nm". It's easy to tell which are the right ones because they will look black. Some other options that also block visible light and pass IR:
Disassemble a remote control and put the plastic IR pass filter over your lens.
Use a security camera dome.
Cross photographic ...
The ideal material for working with infrared radiation (lenses, prisms, windows, etc.) is germanium which does not pass visible wavelengths. If you cannot find what you want in lens catalogs, you can have most anything made to order.