looks like grease on rail
don't use grease
don't use synthetic

If it is grease could explain it, grease will get sticky after awhile. Most ecospaces I have have little plastic auto oilers on top of the guide shoe and call for a kone specific rail lube

Is there normally a lot of pressure on the guide shoe side to side normally?

Those guides are very common to fall apart. The best thing to use is kone rail lube (konespares part #US53940001) or I prefer to use marvel mystery oil. The biggest thing is to not have grease on the rails/guides since it could speed up deterioration of the slides and could cause the safeties to fail. Also, it's VERY common that the car is twisted rather than the rails being out of alignment. Honestly, I've yet to see a kone unit not twisted. You'll just have to replace the guides every few years

The Kone MRL not only saves MR space but uses motors with small HP that require little power.
That's why they have designed a special command in the LCE to "jog" a car off the safeties (full load testing maybe?) as not much power is available.
Power savings = money savings = selling point long term over hydro's.
Cabs are very light boxes and roped 4:1, 8:1, etc
Like any elevator, empty car down is the most power a machine will ever use/need.
If an empty cab does not move (when the demand is down) for even the slightest moment there will be a mismatch between encoders.
It thinks: one's moving, one's not. You're done.
Grease or dry rails can cause this delayed movement of cab.
As mentioned: Use lube devices designed for the purpose of running up and down the hoistway leaving a light film of oil on rails.
If you have a unit that parks for a long period of time, minimal use environment, it will not oil rails properly.
These elevators are slow.
Guide inserts should not be that big of a deal.