OH 4 Rollershutter Position Emulation Profile Service with uncalibrated Shelly 2.5

Did anyone get the “Rollershutter Position Emulation Profile Service” to work with a Shelly which is not calibrated (and cannot be calbrated).
My configuration is as follows:
Item:

Rollershutter      rsMarkise5vR     "Markise 5 von rechts [%d%%]"     (gRsMarkisenTerrassendach_oben)     {channel="shelly:shellyplus2pm-roller:shellyid1234:roller#control" [profile="transform:ROLLERSHUTTERPOSITION", uptime=62, downtime=62, precision=1]}

When I send a command to this item now, e.g.:

rsMarkise5vR.sendCommand(5)

I get in the log:

2023-09-02 21:27:07.445 [WARN ] [y.internal.handler.ShellyBaseHandler] - shellyplus2pm-shellyid1234: FEHLER: Der Befehl 5 für Kanal shelly:shellyplus2pm-roller:c049ef879fb4:roller#control kann nicht verarbeitet werden - POST http://192.168.0.69/rpc > Precondition failed: Cover must be calibrated!

"Der Befehl 5 für Kanal shelly:shellyplus2pm-roller:shellyid1234:roller#control kann nicht verarbeitet werden " means in english: command 5 cannot be processed.

Anyone a good hint for me or maybe another solution?
I am on Openhab 4

Just out of curiosity, why can‘t you calibrate a shelly 2.5?

Shelly controls blinds on a patio roof, the blinds are connected to N and L always, as they have also a remote from the supplier.
They also have two control wires for up and down like a roller shutter, where the Shelly is installed. When the Shelly gives power to one of the control wire, the blinds move, but they “draw their energy” from L, not the control wire. So Shelly can’t measure that and calibration relies on this measurement.

In fact my Shelly can only handle UP, DOWN, STOP and I hoped to find an emulation for position with this feature here.

If I am not mistaken, you can set the “working” time manually.

I know only the option of movement time limits. But this doesn’t help with “emulated position”

Shelly also says on their calibration page “Position control is only available if your cover motors are controlled directly (not through external relays) by the Shelly device and have integrated limit switches.”
And in my case I have something similiar to external relays from what I understand.