Speaking of nonsense, your comment fits the bill exactly.
Do you deny that the traditional Catholic doctrine is that your superiors should be obeyed to the best of your ability unless they command you to sin?
If so, may I suggest that you read the breviary reading (in the new breviary) for the feast of St. Maximilian Kolbe. (Whether you recognize his canonization or not is irrelevant; he was an honored Franciscan religious superior who was martyred well before Vatican II and never said the new Mass. If he's not a Catholic, then neither is anyone in SSPX.)
If not, then how is what I wrote "nonsense"?
because it is also a sin to bare false witness by signing a pledge you cannot honor as a Catholic.
And the only valid reason(s) you could give for "not being able to honor" a pledge demanded by your superiors is (a) I am not reasonably able to do so; or (b) the pledge is outside the superior's area of competence; or (c) the pledge commands me to sin.
If the "doctrinal preamble" demanded adherence to particular doctrines, then cases (a) and (b) do not apply. That leaves only case (c).
We're exactly back where we started. Do you seriously want to claim that the Roman Pontiff is commanding SSPX to commit sins by agreeing with him?
“Do you deny that the traditional Catholic doctrine is that your superiors should be obeyed to the best of your ability unless they command you to sin?”
I don’t deny it all. But, for any good Catholic to sign off on a magisterial document that states he worships the same god as the Muslims worship is a sin against the First Commandment. Muslims deny the Holy Trinity, the Divinity of Christ, etc.
Now as far as the pledge; unless you know what exactly that pledge is, you’re still talking nonsense. Why do you think the Vatican has insisted that both parties keep the preamble a secret until a deal is done, if ever?
Would you kiss a Koran if a priest, bishop or even the Pope commanded you?
Would you take off your shoes in a mosque and bow towards Mecca?