Your point is valid, maximizing Bitcoin allocation early can accelerate long term gains, but it is also a higher risk approach. The challenge is that without a decent emergency fund, unexpected expenses could force you to sell Bitcoin at an unfavourable price, effectively turning a temporary dip into a real loss.
It's impossible for you to have a decent emergency funds in the beginning of your bitcoin accumulation phase because you need up to a year or two to be able to build up an emergency funds of three months of your income. This is the main reason why it's important to build your emergency funds with the same amount that you are using to DCA for a start til you have built up your emergency funds.
Emergency may come or not, therefore allocating more money to your emergency funds and allow your bitcoin investmet to be two times smaller than your bitcoin investment is wrong because of debasement of fiat currency overtime.
This is sound advice. Indeed, many people are still hesitant about investing because they focus on emergency funds. If you accumulate an emergency fund until you have enough, it will never be enough. So, it's best to invest the same amount as your emergency fund. If you focus solely on your emergency fund, you won't be able to invest, and as you said, fiat currencies will continue to depreciate over time.
So, continue buying Bitcoin through DCA every month, equal to your emergency fund. I mean, don't get caught up in preparing an emergency fund and miss out on opportunities to invest in Bitcoin. Emergency funds are important, but you must also allocate your income for investing after allocating your emergency fund and your needs.