Thank you for your email about whether you are bound in conscience to adhere to Traditionis Custodes.
The answer is No; certainly Not; and Of Course Not.
We need to look at the document of 1570 Quo primum tempore, which S Pius V put right at the front of his own edition of the Missale Romanum.
QUO PRIMUM: THE WRONG ARGUMENT
Sometimes traddy people quote stuff towards the end where S Pius V appears to condemn anybody who makes any changes in his 1570 Missal. But he cannot have meant to forbid a gentle evolutionary process ... an additional Festival here, an occasional new Preface there ... because every pontiff since his time has made such changes ... if they have lived long enough. It's what happens in traditional lived Liturgy.
QUO PRIMUM: THE RIGHT ARGUMENT
What S Pius V ordered does, however, bear strongly on the issues in play today. But we need to be quite clear what S Pius actually said. Please bear with me.
Both Bergoglians and some Traddies are currently writing as if S Pius V in 1570 "permitted" rites with more than 200 years behind them to continue.
He did not.
He ORDERED such old rites to be continued. Nequaquam auferimus were his words ... auferimus means "we take away", nequaquam means "not at all".
What he did allow was his own new 1570 Edition to be brought into use if a bishop and his entire Chapter agreed.
Just imagine this scene in 1570:
New Trendy bishop ... wants to bring in the 1570 Missal ... Chapter, load of cringing cowards, say "Yes Bishop Of course Bishop Anything you say Bishop What shall we lick next Bishop". But, over there sitting in the corner, sociably passing wind, is old Canon Lostitzio. He's pretty gaga ... senile, almost ... and drunk most of the day from breakfast onwards. Not even his wife can keep him off the bottle. But he won't agree to the 1570 Missal. Last time the bishop very coaxingly spoke to him about "Our Diocesan Mission Strategy", he just blew some snuff right up the episcopal nostrils and said some unusual words in an obscure Ligurian dialect.
So, in that diocese, there was no Capituli universi consensus. Therefore, in that diocese, there can be no 1570 Missal ... Bishop Trendino and the rest of them will have to stick with their old rite.
That's what S Pius V mandated.
Even if Canon Lostitzio dies tonight, Bishop Trendino still isn't obliged to bring in the new Missal. What S Pius V says is "permittimus". That means "we permit". 'Permitto' is nice old-fashioned Latin verb that popes quite often used, once upon a time. It's still in some of the more old-fashioned dictionaries.
SO: ONE SINGLE OFF-MESSAGE OLD MAN AND HIS VETO COULD PRESERVE THE LOCAL TRADITION OF HIS PARTICULAR CHURCH.
THAT'S HOW STRONGLY S PIUS V BELIEVED IN TRADITION.
QUO PRIMUM AND RATZINGER
When Papa Ratzinger issued Summorum pontificum, he explained to his brother bishops that "What earlier generations held as sacred, remains sacred and great for us too, and it cannot be all of a sudden entirely forbidden or even considered harmful."
Observe that Benedict XVI did not say "It should not be forbidden"; he said "it cannot be ... "
From 1570 until 1970, Quo primum stood at the beginning of every Missal of the Roman Rite.
Pope Bendict XVI, in his own words, in our time, has reiterated its assertion of the essential, theological, primacy of Tradition.
Is anything else needed to make clear that this is the settled doctrine of the Catholic Church?
QUO PRIMUM AND BERGOGLIO
Are you obliged to obey PF if he attempts to prevent you from using the Traditional Form of the Roman Rite? Most certainly not. He is only the Pope; he has no right to overrule Holy Tradition. A pope cannot "do anything". (I think I've remembered that from somebody else's words ... I must try to identify the quotation ...)
He has no more right than I do.
He has no more right than your Aunt Mavis does.
He has no more right to order you to set aside Holy Tradition than do Aunt Mavis's little twins Nicolas and Nicola (who, so you tell me, have just started at their kindergarten and are learning to lithp thothe thublime wordth Amo Amath Amat Amamuth Amatith Amant).
Even if all six of us order you to dump Tradition ... Me; Mavis; Nicola; Nicolas; Nicola's teddy-bear Wilfrid; and PF ... and if we all order you simultaneously ... while waggling, each of us, a great big nasty club with a nail in it ... we are all acting ultra our vires.
I expect you will have noticed Cardinal Burke's words on this subject.
Father: May God bless you in His and your most holy priesthood. Remember always that it does not belong to the pope. Mei in sacrificiis tuis sis memor.
Yours in Domino