Hey!
I do have a skr 1.3 in my 3D printer with older standalone TMC drivers (..not sure, but i think the 2208´s) it´s running Marlin 2.0 fine.. had no problems with this board.
But I needed 6 drivers for my PNP, so for my PNP i use the SKR Pro with TMC 2130´s with SPI configuration, Stalllguard instead of limit switches for X and Y, but X and Y are getting re-homed with the fiducial option in openpnp.
The Z axis has an absolute potentiometer wich is communicating via PWM with another subdriver (Arduino Pro Micro), wich is communicating with the SKR Pro via I2C. - So i´ve changed some code in Marlin 2 to ask the subdriver via I2C where Z really is, instead of homing Z. It worked on my bench, but since then I didn´t had time to install it finally.
However, this is not really closed loop, only replacing the homing routine. - But in general I think a good balanced stepper system without closed loop does not "really" loose steps - or there are some bigger problems involved.. backlash for example is something i´ve had a lot more problems with. But of course, it could be nice to have a closed loop system ..and i do have one on my CNC with servos, but it´s a whole different thing, then picking some small parts.
Marlin 2 has an option for closed loop I2C Potentiometers, but i think you need the matching steppers / encoder PCB´s.
I think it is asking the encoder via I2C if the last reached position is the one that was commanded, or - if it´s off - correcting for it. Do you know what type of communication these scales are? - Maybe it´s possible to hack the original encoder part in Marlin..
In general Marlin 2 is a good option if you´re not afraid of changing some parts of the configuration files.
If you have trouble getting openpnp to work with Marlin, you can ask and I can look at some of my files
Steffen