Can a Mystic activate additional Bestial Transformation effects on subsequent turns?

Question

The Bestial Form Immortal Discipline lets the UA Mystic (v3) choose one or more Bestial Transformations:

Bestial Transformation. As a bonus action, you alter your physical form to gain different characteristics. When you use this ability, you can choose one or more of the following effects. Each effect has its own psi point cost. Add them together to determine the total cost. This transformation lasts for 1 hour, until you die, or until you end it as a bonus action.

At level 1, a Mystic has 4 psi points, but a limit of 2 points to spend per turn.

Could a Mystic activate a Transformation (ex: Amphibious), then on the next turn, another one (ex: Swimming), but without losing the first one?

Answer 1

Yes, since Bestial Form does not require concentration

On pages 9 and 10 of the UA article, combinations of disciplines when spending psi points is covered.

Using a Discipline

Each psionic discipline has several ways you can use it, all contained in its description. The discipline specifies the type of action and number of psi points it requires. It also details whether you must concentrate on its effects...{snipped for brevity}

How do we know if we need to concentrate?

Concentration

Some options require concentration to maintain their effects. This requirement is noted with “conc.” after the option’s psi point cost. The “conc.” notation is followed by the maximum duration of the concentration. For example, if an option says “conc., 1 min.,” you can concentrate on its effect for up to 1 minute.

Bestial Form does not have the notation of "conc. {x time}" on page 11.

Can we combine two options from one feature? Yes.

Combining Psionic Effects

The effects of different psionic disciplines add together while the durations of the disciplines overlap. Likewise, different options from a psionic discipline combine if they are active at the same time. However, a specific option from a psionic discipline doesn’t combine with itself if the option is used multiple times.

As long as you use two different options, you aren't "combining it with itself." In your example, you can combine the amphibious with the swimming and spend 2 points for each, and have them both active at once with the first expiring just a little before the second. (Let's say 6 seconds, to align with the action economy).

Answer 2

I disagree with KorvinStarmast. The section about combining psionic effects is relevant but the "discipline option" here is not amphibious, climbing, flight, etc. it is Bestial Transformation. So triggering a new effect from Bestial Transformation would end the previous effect. The only way to have multiple bestial transformation effects would be to activate it at the same time within the Psi limit.