There seems to be many spurious reasons given for the change in RCD/RCBO testing, but I think the true reason was to make testing quicker & cheaper.
No, you will not damage a RCBO testing it at 5*In as
@James points out that is something like 40,000 times smaller than the rated ultimate breaking capacity.
No, you will not wear it out either under any sane regime. Looking at a typical data sheet (ABB came up first in google) they often are rated for 10,000 electrical cycles (i.e. operating at rated load of tens of amps) or 20,000 mechanical cycles (operating with negligible load).
If your traditional test was two 'In' trips (0 deg/180 deg), two '5*In' trips, and a test-button trip, along with maybe initially isolating for other tests, that is 6 cycles. To wear it out you would need to do that 3,333 times. If you did that test on every working day in a year (around 200) it would take you 16 years.