If you still have the stock Bosch 233 regulator then yes, a new adjustable regulator would be preferable. If you have the Bosch 237 regulator you might be able to get by with that only thing is its not adjustable.
A Bosch 237 will give you the proper base fp (~43 psi) for a turbotweak chip. It's a good inexpensive option for someone who wants to keep things simple. Depending on your goals you may not even miss not having an adjustable one. Just adjust fuel through the chip if needed. In certain applications its nice to keep things simple and not have too many things to adjust or worry if its adjusted right. All depends on your goals.
I feel like the fuel pressue, as adjusted at the regulator, is more of a "gross" adjustment, for whatever chip. One that baseline is accomplished, then you can "fine" tune through your chip, translator, etc.
I consider it an essential upgrade, for whatever it's worth
You can "adjust" your regulator with a vice and right size socket. Careful as you can't go back down. But if you are willing to do the extra effort it is cheaper than a $100 upgrade and does the same thing(increase base fuel pressure).