Iets do some math to see if this would be a problem

Calculation assumptions

1 every attack hits

2 all damage calculated is with the median roll rounded down as per the rules

3 if i change the calculations i will tell you before laying it out

So a 20th level soulknife 9 psi warror 11 can take 3 attacks per attack action with maxed out dex that means that the damage for the round if more than one psychic blade for all the attacks is 24 damage and 2 extra with the bounus action attack

Now lets check with Psionic Strike.

Feature description

You can propel your weapons with psionic force. Once on each of your turns, immediately after you hit a target within 30 feet of you with an attack and deal damage to it with a weapon, you can expend one Psionic Energy die, rolling it and dealing force damage to the target equal to the number rolled plus your Intelligence modifier.

Heres the math 1d6 median 3.5 rounded down to 3 +5 STR/DEX per attack plus 1d10 median 5 + 5 INT per attack leads to 54 damage per attack action plus the bounus action attack 1d4 median 2 1d10 median 5 +5 INT

IMPORTANT NOTICE

This course of action will burn through your psionic power dice which have the same name and may not stack but take the best bounus of dice rather than give you 2 sets of Psionic power dice set one soulknife 12d8s psi warrior 12d10

You would only be able to do so for 3 rounds before you are complete out of psionic power die unless you are allowed to use both sets ither restrictively or free flow either way you would be using limited resource that come back on a short rest so you can more or less treat it like a pallock’s use of eldritch and divine smite just with less effect

Now to asume max damage on a regular strikes the math would be 1d6+5×3 or 18+15 = 32 damage; with the bounus action attack 1d4 32+4=36 psychic damage in a turn

Now max damage with psionic strike

1d6+5+1d10+5 or 6+5+10+5=26×3 for 3 attacks = 78 damage with the bounus action 1d4+1d10+5 or 4+10+5=19 for a total of 97 damage in one turn

Now for max crit damage

2d6+5+2d10+5 or 12+5+20+5= 42×3= 126 with the bounus 2d4+2d10+5 or 8+20+5=33 for a total of 159 damage in one turn

Either way just thought someone should do the math just to see what it would be