If you're just starting out, maybe it's worth taking a risk to invest sooner.
Longer term, losing or quitting your job is a risk you should consider. Longer term, your investments will probably be larger, and the 1.5 year loan trick will only add a tiny amount - while adding to the risk of repayment if you lose your job. Some people discover the hard way that stock market crashes and job losses are more likely to occur together. That's not a good time to sell investments to cover expenses. But it's a risk that may or may not occur, so when you don't have any investments, maybe it's worth taking that risk to jump into investing with 1 year of income.