When Briggs took over Simplicity they made very few changes.
I am assuming that it was part of their vertical intergration plan to ensure there will always be a market for their engines.
implicities were never that, Simple, but they are excellent mowers and that one should be around long enough to mow the grass over your grave.
AS time goes by more & more moron lawers keep getting cases in front of bleeding heart judges who award silly compensation payouts to people who really should have either been allowed to die of fined for their own stupidity.
Thus to prove the mowers are being made idiot proof, they get more & more complicated and you can expect this to happen at an accelerating rate.
Simplicity has always been a top end mower so if the perfect design requires 15 idler pulleys, then they fit 15 idler pulleys.
I am always reminded of a customer with an old Bolens.
His father had bought it, when he moved onto acreage and he had now inherited the mower & the estate.
It needed a new belt, the first one that had ever been put on the deck so it had run better than 20 years, but fitting it was a nightmare as there were pulleys & guides everywhere so when the deck moved through it's 6" cutting range the belt run remained almst strait from one pulley to another.
Now days to cut cost they just fit deeper grooved pulleys which wear out belts 50 times faster.
I use a yard crane to lift the mowers up so I can get underneath them comfortably and for tractor type mowers that might mean standing them up near vertical
Inside the shop I use an engine crane for the same purpose.
We use an old Dexion pallet racking beam as a spreader bar and with that I can lift the entire mower 4' in the air.
A younger friend drives his mower up onto his tall trailer then he puts stands under the ramps and runs off the trailer so the mower is sitting about 2' off the ground to work underneath it.
The real question you need to think about is how comfortable the Simplicity is for you to drive now and in the future.