Go into detail of how/why you cannot "walk reliably" without aids, then also give details of why you could also not "walk reliably" using aids.
This way, you can pre-empt The PIP Decision Maker assuming that it would be "Reasonable" to determine that you could "walk reliably" using any applicable walking aids.
If necessary go into graphic detail, do not work on the premise that the DM will make any positive assumptions in your favour.
