Can A Psionic Talent Be Cast Wearing Heavy Armor?

Question

As most of you know, according to the Player's Handbook, it isn't possible to cast a spell while wearing armor you aren't proficient in.

Have there been any rulings on this in regards to expending psionic focus, or using a psionic spell? Check this excerpt from Unearthed Arcana:

Psionics and Magic

Psionics and magic are two distinct forces. In general, an effect that affects a spell has no effect on a psionic effect. There is one important exception to this rule. A psionic effect that reproduces a spell is treated as magic. A psionic effect reproduces a spell when it allows a psionic creature or character to cast a spell. In this case, psionic energy taps into magic and manipulates it to cast the spell.

Answer 1

Yes, you can use any and all psionic abilities while wearing heavy armour. It's difficult to prove, but the article doesn't mention anything about armour constraining psionics. Similarly, the handy Sage Advice site built a collection of Mearls' tweets on psionics, and none of them mention anything, either.

Note that if you wear armour that you aren't proficient in, you will suffer the normal penalties of non-proficiency:

If you wear armor that you lack proficiency with, you have disadvantage on any ability check, saving throw, or attack roll that involves Strength or Dexterity, and you can’t cast spells.

It's worth noting (on top of that first note), that this won't really affect your psionics at all, since the attack rolls you make with psionics are Intelligence-based, not Strength- or Dexterity- based.

Answer 2

Wearing armor wouldn't prevent you from manifesting a power, but you would however suffer the effects of wearing armor you aren't proficient with if you end up having to roll an any ability check, saving throw, or attack roll that involves Strength or Dexterity.

The reasoning being unable to cast spells in armor untrained in the first place is that spells of the arcane variety have precise somatic components (commonly described as arcane gestures or hand wiggling) that have to be done that encumbering armor interferes with.

A spell is a spell and a power is a power. Spells are drawn from inner channeling or altering of magic using gestures, words, or focii. Powers are created by harnessing the mind to manipulate the nature of reality or the ego of another person or thing. The two mutually exclusive from one another. After all, you stated yourself that it isn't possible to cast a spell while wearing armor you aren't proficient in. You also mentioned that "an effect that affects a spell has no effect on a psionic effect."

Since Armor and encumbrance is an effect that affects a spell, it has no effect on psionics. (Unless there's some kind of unmentioned Psionics-Magic Transparency going on in your game that hasn't been mentioned)

However, the final call of whether or not a situation is advantageous or disadvantageous lies with the GM of the game.