How can I seek permanent Personalised Assessment Arrangements, rather than reapplying each year? I'm severely disabled. Under Outcomes and length of arrangements:

If your condition is long-term and unchanging, the Personalised Assessment [henceforth PA] Arrangements Committee (PAAC) will approve arrangements for the duration of your programme, meaning you do not need to reapply each year.

Under 3) International student:

You can apply to sit your examination at an alternative venue [henceforth AV] if you are either:
a)      Taking a resit and/or replacement examination and you are a non-attending student. You can only apply to sit in your home country.
OR
b)      Taking a resit and/or replacement examination and you are applying to take the examination during the August exam period. You can only apply to sit in your home country.

I asked King's College London (KCL)'s Exam Services why AV can't be approved permanently (for the duration of my degree), like PA. But the Head regurgitated without explanation that this is possible only for PA, before harshly alleging that this matter was closed.
How can I challenge them? Can the Equality Act 2010 help?
Additional Argument, in addition to inability to live alone long-term.
Requiring me to reapply each year throws my life into uncertainty, thwarts me from planning how long to rent my apartment, and and forces me to rent for longer than needed. How?
Option 1: I lease until June, as I wouldn't know if AV'd be approved this year when I sign a lease. But if I learn that I'm approved for AV no earlier than Jan. or Feb., then lease payments from Mar.-Jun. would be wasted as I'd fly home.
Option 2: I lease until Mar. 2019. But the risk is lacking residence in London, if my AV is denied and I need to write exams in London in June.
A quick review of the link you've shown suggests that the two classes you've listed, personalized assessment and alternative venue, are open to two completely different groups:


Personalized assessment is for students with recognized learning or physical disabilities;
Alternative venue is for international students.


You're effectively trying to conflate the two types of accommodations, by requesting an alternative venue as a means of handling your disability. Based on the response of the chair of the committee, they are proceeding according to this distinction. For this to be successful, you need to be able to explain medically why you need to be at home for the exam period. Raising financial costs as a reason will not be a sufficient reason—by that rationale, you're no different from any other applicant wanting an alternative venue.