VEC chart, page-145

Not sure if everyone knows how ASX/CHI X interact.

If your broker is a participant of both ASX & CHI X (which most brokers are including the 3 major retail brokers, Commsec, ETrade & NAB Wealth) then when you put in an order to your broker to buy or sell it firstly goes through what is known as a "smart order router" at your broker (this bit of equipment is compulsory and allows for what is known as "best execution" in the market). Best execution just means getting the best available price.

When your order hits the "smart order router", it determines where the best price is - on ASX or CHI X and will execute at that best price. Your order may even be dealt partly on ASX and partly on CHI X but that doesn't really matter,

Here are the CHI X participants - https://www.chi-x.com.au/trading-information/trading-participants/

So no broker can use say CHI X and not ASX - it cant be done. Only time an order can be executed only on CHI X is if a broker is a member of CHI X only (and not ASX)