Sorry but I don't get it. Naturally you make snake-like maneuver, because going 3 tiles straight is 8+8+4 = 20 TU, while hopping off then hopping in is usually 6+4+8 = 18 TU... (plus free scouting!). To really 'fix' that you would need to completely rewrite the basic mechanics of the game (in this case, rule of: "the cost of movement is the cost of entering a new tile").
The slowing-down effect of the ramp is important tactically. The 'fix' destroys that feature. Also what makes you think the AI uses different pathfinding than auto-pathfinding given to the player? Does it even remotely matter?
So, it is realistic that a longer way, a detour, a jump and another detour BACK to the straight line take LESS time than a simple run DOWN a ramp?
And why should a ramp DOWN slow you down? I simply don't understand the logic behind all this.
It looks strange that every time you want the unit to run down the ramp it does the snake-dance before it goes back to the line it was supposed to use.
Well, I agree that the free scouting is convinient, true, but it does so at the cost of precious TU, which will lead to more reaction-fire AND one could easily scout/look manually at a lower TU cost.
Anyway, I see you want the ramp as it is for other reasons than TU-logic, I can accept that. (Still will use the fast-ramp for myself)
And what I meant about the pathfinding^ is that it sometimes happens that the autopathfinding finds a faster way than the user would BY HIM/HER-SELF, nothing more nothing less. And yes, that does matter, as it can save your unit's ass.