Vivosun 3in 1 tester.

I have noticed in a few images the placement of the Vivosun 3 in 1 tester in potted plants. They seem to be a permanent placement in the pot. The Vivosun says they should not be left in soil. Only to test and then remove and cleaned. Is there a downside to leaving them in position?

Think it is a neat idea to 24-7 monitor with them, just wondering if it would give false reading or die prematurely.

The probe will develop a film on it, and needs to be cleaned regularly for accurate readings