From the link posted:
"However, the speed and convenience of these tests comes at the expense of accuracy, meaning care needs to be taken in the interpretation and communication of results."
Precisely. However, if it makes you feel good, then that is a good reason I guess. If you are happy about the prospect of self-isolating then, again, no problem.
And presumably if you AREN'T happy, then you won't be bothering.
Are the PCR "second opinion" tests free?