On all foils I have ridden, I stand with my rear foot behind the mast, most of the time.
Doesnt matter if a small wing less than 600 cm2, or a big 1200 cm2 one.
But of course, the smaller the stab you use (typically with more experience as more lively), the further rear you stand.
Only if I stand with both feet together, it is on top or in front of the mast.
Apart from that, for bigger boards, you can ride in marginal winds easier, having a tad of board behind you, as you wont sink the tail in the lulls, and in the puffs you can get up flying, WITHOUT moving your feet first.
Too much is no good of course, as you can not pump if too much area behind the mast, so there is a delicate balance, depending on your boardsize, and current foil as a bit variation in center of effort (but not much really, most are pretty equal)
On my current Ketos foils, I sometimes stand with rear foot at the trailing edge, either when standing with a relatively wide stance, or sometimes when doing 360's up in a wave.
Also, it is very unpleasant to stand just next to the trailing edge for me - it is just like if you stand with your front foot at the very edge of the grip or deckpad - NOT fun
The boards with tracks I have seen, are mostly centered around the same spot so beginners can move it further rear so they dont foil too easily, and advanced can move it forward.
And to accomodate different brands slightly different center of effort, and also stab trim settings.
These pics illustrates one type of stance, not superwide, but quite wide yes, and goes for most foils regarding trim.
Yes you can stand on the mast also, if you ride with either a narrow stance, or a foil which has been trimmed "up" for learning, meaning stab pulls down so it tends to pop up/out of the water at higher speeds.
The more experience you get, the further rear you stand.
On the other side, the more experience you get, the more narrow stand you also use when you feel like it ha haa
Also, if you want to ride the shortest possible board, standing narrow and a the very back of the board with rear foot, is a necessity.