Your statement:
Just for reference, Spanish mode recomendations (as provided by URE) are:
5.351.5 to 5354.5 Khz CW/Digital narrow modes
5.354.5 to 5.366.5 all modes.
I find a little confusing given that the IARU R1/R2 bandplan for 60m is as below:
As you can see 5366 - 5366.5 is intended for Digital weak signal modes - not all modes - have the spanish authorities moved this down the band and “tacked” it onto the end of the CW section?
Also 5.366 KHz SSB is not going to work for SOTA as 60m is Upper Sideband and you need to add at least 2.7kHz to that frequency - making the top of the signal 5.368.7 which is out-of-band!