Staircasing on HTB

Hi guys,

Just in the midst of completing my first house purchase, and have been crunching numbers.

Just wondered whether the below scenario have ever happened or if anything knows about anything of it? (lots of assumptions here, bear with me pls)

So i've now taken a HTB equity loan of 20% for a new build, i've heard or seen many ppl saying new builds arent worth their prices and they tend to drop in valuation within the 1-3 years, only if we hold it long enough it will hopefully stay or go up.

Now based on the above assumption of it dropping within the first 3 years, would it be better off for myself, (if i were to get a substantial cash) to redeem the 20% off HTB within the first 3 years? As i read HTB will only allow u to redeem it based on market value, and not based on the equity loan on purchase. Assuming the market value would have dropped, and if i were to redeem it then, it would mean i've saved some money in the long run?

Any thoughts on this?

Cheers in advance.