I'm not totally sure of what you are saying.
I'm imagining a flange with slots?
The closest bolts slid into the slots, and they can flop around.
Most plumbers use bolts with extra nuts and washers, that way they can secure the bolt to the flange before the bowl is set down.
Not that they "need" to be secured, but it is nicer that way, especially if the bolts need to be sawed shorter.
We like to try the bowl on the flange first without wax, to see if the floor is level. If the bowl rocks, we place shims near the back, pinning the front of the bowl down to the floor,
Pull the bowl up, set the wax down, and set the bowl.
If the flange is above the floor level, one wax seal will do.
If the flange is recessed, we stack two wax rings.
If you are using a flexible supply, don't use Teflon tape with them, they will have seals on both ends, and the tape prevents those seals from touching.