Love the ambition!
A huge part of success is setting attainable goals and having realistic expectations about what it will take to reach them. Under 20 seconds for a deck is world champion level pacing, which is a great aspiration, just make sure you set yourself some “checkpoint” goals along the way to that destination.
Couple questions for you…
How long have you been working with memory techniques? (Specifically cards, numbers, and memory palaces.)
What are your best times for a 100% accurate full deck run? 10 minutes? 5 minutes? Are you already able to go under 1 minute?
Knowing this will greatly help us be able to offer suggestions.
Disclaimer: I haven’t achieved a sub-20 second time for a deck, but have been able to go under one minute using a couple different systems, so I think I can offer some useful tips to at least get you towards that!
Definitely don’t try to create new on-the-spot palaces every time. There is almost no way that will get you to your time goal.
The advice I usually give is to pre-determine at least twice as many palace journeys as the number of times that you want to practice a deck each day. This way you can rotate your palace use and allow a day (at least) of downtime in between each palace use to help cut down on “ghosting” and interference with imagery from prior runs. This is especially relevant if using a single card system like PAO as you’ll have many more repeat elements than with say a 2-card or 2-block.card system.
Absolutely pre-create these palaces and practice navigating them “clean” often until you reach a point where you can basically “blink” between your loci. In order to hit a sub-20 time using 17 loci journeys, you only have about 1.15 seconds to spend at each loci. That time needs to include reading/recognizing the cards, formulating the PAO scene, setting it in a memorable way within the location, and navigating to the next location. The loci navigation should be the fastest part of this process because it will be the only “constant” factor that you’ll be able to know ahead of time. There should be zero hesitation about which locus is next in the sequence and you should know it well enough to be able to nearly instantly draw out a connection from it that points you to your mnemonic imagery. Memory palace training is just as important as learning your P’s and A’s and O’s.
This is important, but it is really important that your practice is efficient. Make sure you are randomizing the cards you are training. Make sure you are trying to recall the P or the A or the O DIRECTLY from the card with as few extra “conversion steps” as possible. The goal will be to be able to instantly visualize the specific element needed from the card without having to first reference back to something else to trigger it.
What system are you using to determine your imagery for each card? Category, Number (Major, Dominic, or other?) or something else?
Is your PAO structured so that you “read” the person from the card and then have to determine what that person’s action or object are to arrive at the needed element, (like "Einstein / Writing / Blackboard)? Or are you able to “read” each element independently (like "NiCK / kNoCK / NuKe)? Either way can get you to instant direct association, but one may be faster than the other to arrive there.
As far as your Q2 goes, this forum has TONS of amazing people and free resources to help get you where you want to go. I’d start with what you can find here and see how much effort you’re willing to put in and how long you can tolerate sustaining it. As far as I know, there is no hidden secret to achieving ultra-fast times. Its like any other acquired skill. Tons of practice is needed. You can do it if you are determined to.
Here’s some info about managing expectations for learning a number / card system to various stages of fluency:
And some thoughts on effectively practicing a PAO:
Best of luck!