Since when has it been OK for Roman Rite Catholics to attend any other valid rite?

Ever since the thermonuclear ɧơƖơcαųst of Vatican II was detonated. Welcome to the New Springtime!


BTW not trying to be sarcastic with you M.

Not trying to be sarcastic but.......says who?
 Who released Catholics to make their own decision as opposed to their bishop?

Pope St. Pius X & Pope Benedict XV

CIC 1917
The custom, no matter of what duration it may be, to receive Holy communion in another rite does not entitle to, or mean , a change of rite.

http://archive.org/details/newcanonlaw00woywuoft/page/18/mode/2up?view=theater


709. All the faithful of any Rite are given permission for devotion's sake to receive the Blessed Sacrament consecrated in any Rite.


http://archive.org/details/newcanonlaw00woywuoft/page/174/mode/2up?view=theater


IOW receiving communion, which normally involves attending the liturgy, is permitted and does not mean that a person is formally changing rites.

True when travelling it was wonderful to see all was the same.
However we were actually forbidden to go to confession outside our parish (unless we were travelling) and if anyone was ever denied absolution you were forbidden to go to another priest in your parish but had to go back to the one who denied you absolution.
In the book Catholic Practice it speaks of not leaving your parish on page 25 as well as other places in the book.
All I've stated above can be found in that book which most people had back then prior to Vat II.
It was a totally different world.

Is this the same book M? Looks very interesting and useful.

https://archive.org/details/CatholicPracticeAtChurchAndAtHome/page/n7/mode/2up

Different edition but looks like the same book.

I have never heard this before.
Actually we would not even think of attending a different parish. There was no smorgasbord when I was growing up. No need to pick and choose, but we now live in a different world. If you were travelling or away you went to the nearest. There were no differences parish to parish apart from the sermonabilty of the pastor. You were safe wherever you went.

I have also never heard of a prohibition, and I'm a cradle trad.  There was an expectation -- most of it logical -- that you would attend the parish closest to you.  But doctrinally orthodox parishes were everywhere; none preached heresy or said "a new Mass."  I would say you were expected to accept the local parish God gave you in submission to His Providence and to counteract any spirit of willfulness, but the only cross suffered was the particular personality of the priest and his teaching style. As now, some priests were unhappy, other priests were boring, and others were inspiring, but ALL of them were faithful and could be counted on to tell the Catholic truth straight-up.

Families with lots of young children sometimes have trouble getting it together to get to a particular church on time for that Mass -- hence the convenience of so many options within 5-15 minutes' driving distance.  So that was the reason we sometimes didn't go to our most local parish, one mile away.