I've read up on loading Flash Boards. The term "pointers" is often used. Is the following understanding correct?

2 things are loaded into the Flash Boards. SAMPLES & WAVEFORMS.

SAMPLES are the audio files.
WAVEFORMS are the "pointers". The waveforms provide the instructions to the XF on how the samples are played.

This is essentially correct. Samples can be in .wav or aiff formats... a sample is an audio recording done a sample rate and bit depth (44.1kHz and 16 or 24 bit)
A Waveform is the parameters that the XF applies to these samples that collect and organize them into playable entities. Waveform parameters include an association with a KEY (1-128 or musically C-2 ~ G8) that will determine its original pitch. Each Key you play higher or lower will adjust playback so that pitch changes 1/12 of an octave (default tuning). Other Waveform parameters determine what VELOCITY (1-128 or musically how loud) it sounds, what PLAY DIRECTION (forward one shot, Loop, reverse)...

Almost any device (phone, computer, tablet...) can playback a sample .wav or aiff... the “Waveform” is a set of parameters that turn it into a collection of musical items that can create a playable instrument. All the parameters that frame the audio are tiny (minuscule) in comparison to the audio they collect.

On an analog synth, like a MiniMoog, you selected a Waveform on which you built a sound... it was a sawtooth or pulse wave variation that you used a filter, an amplifier and EG to shape it into a sound. The Oscillator (sound source) Waveform was generated by voltage control. A synth is really like a electric circuit with a buzzer connected. Complete the circuit and the buzzer goes off. The Keys of the synth act as “gates” to let allow you turn off and on the signal at command. The other devices, filter, etc shape the result. The voltage is precisely tuned so that for every octave you go higher requires another Volt

In a sample playback engine, like AWM2, the Waveform is assembled through a set of samples... instead of a buzzer circuit based on voltage, you substitute a set of digital recordings mapped to be musically useful. The other devices filter, etc, shape the result, as in the analog synth.

The most important screen to “get” is the VOICE > Oscillator screen
From an XF normal Voice
Press [EDIT]
Press [1] to view Element 1 parameters
Press [F1] Oscillator

The Wave Bank “points to” the Bank (Pre, Usr, FL1, FL2) where this Element is going to find its sound Source... Waveform (collection of samples)
The Wave Number singles out one of those collections of Samples

So very much like an iceberg all the other parameters that address this Waveform and the samples it is organizing, amount to a small data size (around 2KB), meanwhile... the Oscillator itself could be huge 400MB (Chick Corea Rhodes, for example)

Sample = digital audio recording
Waveform = collection of samples musically arranged
Element = each Element references a Waveform, but adds additional parameters for tuning, and Pitch EG, Filter, Filter EG, Amplifier, Amp EG, LFOs. EQ, Etc.
Voice = acollection of 8 Elements in a Normal Voice, 73 in a Drum Kit Voice, but also adds Effects, more EQ, Controllers, etc., etc.