If you click on the 3 dots next to your email in the bottom left, you can set "custom instructions" now. Basically, you can tell ChatGPT who you are, as well as how you'd like it to respond.
And of you use the playground or any of the third party ChatGPT frontends that use the API you can just set the system prompt accordingly (custom instructions is basically just the system prompt). It'll still apologize here and there, but if you tell it that it's now a low level systems engineer AI, it should stop lecturing you about the dangers of low level systems engineering.
It's not perfect but it's coming along.