Short answer: yes, it serves me very well.

About a year before before the pandemic hit I always went to the PO to lodge my parcels which would include a lot of international ones.  Then I got the idea of walking the dog to the red street box and putting them in there, and discovered that this was perfectly fine, and now I ride my bike there and do it too.  They got scanned in that afternoon when collected by the 12 pm time, but since the pandemic hit it's been the next day.  I've been doing it since, absolutely no problem except one period last Xmas where they would all turn up on my doorstep the next day but that was a sorting error which quickly got fixed.

Just make sure you get the weights right and ensure you sign and date them, and also put the customs copy in the plastic pocket thing if required for some countries.  These are things they check at the PO but will be now up to you.  I recommend you bring a pen with you and double-check as you put them into the box, in case you missed one.  It has caught me out a couple of times.