I agree. Your argument, here, is much more solid than saying a free-for-all is legitimate.
For priests operating during the known Crisis in the Church (post-Novus Ordo Missae), one can see the Modernist origins and therefore prune everything off tainted in this way, assuming that a future authority will fully agree with you. After all, "the good of the Church" is the highest law. Once authority becomes legitimate again (by once again seeking the good of souls, the good of the Church) this authority will HAVE TO WANT such a rejection of error.
How is adhering to tradition a "free for all?"
The traditional Holy Week rites are certainly covered by Quo Primum, which stated nobody needed permission to say that missal.
Lad, by implication, seems to think Quo Primum, therefore, commenced a free for all, which is stupid.
Conversely, it is debatable whether the modernist 1956 Holy Week -in such measure as it substantially deviated from that missal, and in fact created a Novus Ordo of Holy Week- is covered by Quo Primum.
So as usual, Lad the great sede-innovator, sees everything backwards:
Adhering to tradition is tantamount to a "free for all" to which we have "no right," but saying the modernist Holy Week is allegedly obligatory

If there's any "free for all" here, it would certainly be instigated by the liturgical innovators (and those who go along with them), and not those who hold fast to tradition.
Anyone who doesn't get that really has no place identifying themselves as "traditionalist" (of whatever stripe).