ivan_use utilities for custom cross
To elaborate on this, if you are playing in your browser, you can install Tampermonkey, then install Krunker.io Utilities (made by the creator of the official client, I believe)
If you are playing by using the client, the Utilities options are built in. In both cases, there will be a "Utilities" button under the Krunker logo in the main menu. I play with Display set to Custom, Style set to Filled Circle, Always Show active, Color set to green, and Length and Thickness both set to 2.
Both browser and client versions of Utilities also give you the option to set a custom scope image as well as the option to disable black boxes (the black area around the scope when scoping in with the sniper rifle). This can give you a potential advantage due to increased visibility while scoped in. Because this is supported by the official client, it seems that this is allowed, which is surprising to me. To test these options, I created a transparent PNG on my computer using GIMP, then uploaded it to Imgur. I then copied the image URL and pasted it in the Scope Image box. The result with black boxes off is no obstruction of vision while scoped in as Hunter. Use these options while you can, I guess. Based on Twitch streams, I know that at least a few others are doing something like this.
Using Utilities to activate Unlimited FPS is only an option on the client.