Duping Trash Dash with Home Sweet Home after leaving the house and getting in the vehicle will execute a GOTO IF TRUE 8000 command, which will then execute the contents of the variables as code. I looked a bit and the next few variables are all useless (boolean flags or similar) until it hits come uncontrollable variables. The goal is to set $2000 to one of these values (millisecond perfect):

655362 (go to Timer0) 655436 (goto if true Timer0) 655440 (gosub Timer0)

720898 (go to Timer1) 720972 (goto if true Timer1) 720976 (gosub Timer1)

Timer0 resets during the mission, the last time being the moment you get in the vehicle after leaving the house. Despite this, using Timer0 is still faster provided you don't waste too much time in the first part of the mission, since Timer1 requires 65536 more milliseconds.

Then start Trash Dash during the aforementioned mission state with the following values (millisecond value window): 96609 to 96925 (go to Credits - discussion on whether jumping to the legitimate credits sequence without going through the last mission here) 165138 to 165157 (go to Sicilian Gambit)

This video is a demonstration of this:

Note: deathwarp in Staunton can be done by just attacking the shopkeeper Edit: can also just take the boat to Portland, which saves having to setup om0 again and can just go to the safehouse to continue. Timer1 is unusable like this but it's faster to use Timer0 anyway. Edit2: Clipping through the tunnels is even faster:

There's a second known way to do this by using Scrapyard Challenge. However, the wait command required for this one is during the countdown for the sidemission to start, so a method to manipulate this cutscene is required. The current best known solution is to use Avenging Angels to softlock Low-Rider Rumble (the race mission) and then using that to dupe Scrapyard Challenge. Partial demonstration during this video This method requires doing more missions to unlock the races (Vincenzo up to Smash and Grab, Ma until Grease Sucho).

It's possible that there are other, better/faster ways to do this.

A method to perform this more reliably RTA was found:

1. Start Vigilante
2. Start Frighteners This will execute a GOTO TIMER0 command, so you just have to wait for certain times in Vigilante to jump to wherever you want in the script. This can be seen in action in current Any% runs to jump to the credits sequence:

Other examples of jumps include debug menu: And starting any mission (many will probably crash): Starting Bringing Down the House in this way plays out the cutscene and destroys Fort Staunton without passing the mission, making it possible to get the final package (All Hidden Packages runs when). This is apparently also possible with the debug menu.