Freelance work - payment in cash - ACS assessment

Hope everyone is doing well in this pandemic.
I have one of the strangest queries, couldn’t find the solution anywhere, so decided to post it here.

I graduated in the year 2009, and then started working full time (cash salary as it was my very first job) for not so big IT company till September 2013.
Then, I started working full time in one of the public sector banks here in India, but alongside my full-time job, to follow my passion of programming I kept working as a freelancer (more than 5-6 hours a day) for my previous as well as other IT companies, and worked for multiple clients on multiple projects (I can get reference letters) till date.
I can get all the required / suggested docs, as I’m in good terms with all the companies I worked or working for, but all of my payment was in Cash, except from payment of last 8-9 months, as I started to plan immigrating I started accepting payments in my personal bank account.

Can anyone guide me in claiming my work experience as a freelancer and how to prove that to DIBP at later stages of the Visa processing.

Thanks in advance.

It is not possible to prove cash payments as valid payments unless you filed Income tax returns and then showed them on paper some or other way.

Is this extract from ACS assessment guidelines, still valid ?

If yes, then I can arrange those reference letters from all the companies and clients I worked for.

How will you prove cash payments for paid work?

I regularly issued invoices to all the companies and clients I worked for as a freelancer, some of those invoices were for AMC charges.
I used to recieve payments against those invoices in CASH, but I was regularly depositing them into my various bank accounts as individual cash transactions.
Only problem with bank transactions here in India is that, narration in your bank statement depends on the teller who did that particular transaction as a banker.
If I can somehow convince ACS regarding my paid work experience from my bank statements in accordance to the amount claimed in my invoices.

That’s all I can do now alongside getting as many reference letters from my clients.