Selling myself to the bank?

Long story short - 3rd year IBD Analyst here in Hong Kong where my bank offers 100% LTV for employee mortgage. As some of you may know this offer is incredibly attractive as it costs a fortune to even pay off a down payment in HK (in my case it will cost ~ US$250k for a 400 sq ft apartment in downtown.)

So that's where the problem kicks in. By doing a mortgage with my current bank I'm basically selling myself to them as I have to work till I have $250k in savings so I'd have enough to refinance my mortgage with other banks (as in they will require a down payment) if I ever decided to quit my current bank. I consider myself a pretty frugal person but saving $250k in a few years time is no small feat and it seems pretty challenging in a high-cost city like HK.

Reason I'm asking is because I'm not sure whether this is an ideal scenario to commit medium / long term. I'm in a good group with decent deal flow though my MD is simply a pain in the ass to deal with. Toxic culture and tons of micromanagement. Hours are not bad compared to other BBs though it's still IBD at the end of the day and it's physically & mentally draining. I'm not sure if I will be able to commit 3-5 years in a job that demands so much from me, though the temptation of owning a house in your 20s is real and regardless I’ll be buying a flat sometime down the road, so all I’ve been telling myself is to tough it out and grind through.

Any advice? Will love to know all your thoughts on this.