Alright, thought-out post here. Hopefully you won't consider this to be "bad" feedback. I've thought about the problem you are trying to solve, and broke it down.
You said that you want to make a "faster" plr. I think that this is ridiculously hard, and here's my thought process.
The way you are going about doing it, you have shorter paths, and a smaller map. From what I have realized though breaking down and thinking about the problem more and from what I learned from previous stabs at making "faster" gametypes, shorter & smaller =/= faster; especially with plr. When you shorten the path lengths of plr, you are lowering the amount of active, workable playable area (this makes sense because paylod maps and their flanks are built up around the tracks. Less track, less space to build flanks, routes, etc). This also leads to more cramped areas, since again, there isn't a large amount of workable space.
What I can see from your map is that you have a shorter payload path, which means shorter, more cramped convoluted flanks. These then lead to player confusion and tight spaces. Why? Because of "density of routes." (Made that phrase up, but it convey's what I'm saying) If you have a ton of routes in a single area, players could easily confuse their entrances and choose the wrong one.
If routes are too close together, first time players may think that these entrances lead to one single route, and enter them in that mindset. They then get frustrated when they learn that going into Route A does not actually connect them to Route B, but going through the other entrance right next to entrance A, would take them to where they wanted to go. Yes, over time more people would learn to play the map and which routes go where. But if a player is getting frustrated after 2-3 rounds, there is a good chance they will leave the map and not play it again. So, if your density of routes per a single area is high, then there is a better chance of confusion and thus, a player leaving.
Next, with a shorter path, you will get shorter rounds, yes. I do not dispute this. But, if you get shorter paths, then gameplay and flow changes rapidly. Think of it this way: The goal is to prevent the other team from pushing the cart to the end. Shortening the path means you have a shorter time to stop the opposing team. The teams are essentially on equal until the cross-over. But, whoever wins the cross-over then gets the automatic offense advantage, and the losing side must immediately go on the defense, due to respawn time, and number of players. (if this didn't happen, then it would just be a game of "who can get the most people on the cart". The answer to that again is the team that wins the cross-over).
The way your layout is set up, the team who wins the cross over, gets an relitively large advantage when pushing, and then gets the higher ground. If you look at hightower, the amount of time it takes to push the cart from the cross over to roughly the curve before the bottom of the hill, is about the length of the opposing teams respawn time. This can't be coincidence. This gives the cross-over losing team, and way to re-gain an advantage, because the cross-over winning team needs to be at roughly full strength to get up that hill. (this also allows the losing team to set up some sort of defense for the same reason). you also have sightlines galore, which aid the cross-over winning team in offense.
I'm sure if you look at your demo(s), you'll see that a majority of the time, whoever wins the cross-over usually wins the map.