Solution

The grid can be filled with words/phrases according to the Across clues and then subdivided into the provided pentominoes (without rotations) in such a way that each pentomino contains the 5 letters of one of the other clues.

1	B	A	T	T	L	E	S	H	I	P
2	O	U	T	P	H	Y	S	I	C	S
3	P	L	E	S	I	O	S	A	U	R
4	P	E	R	P	L	E	X	I	N	G
5	S	A	L	A	M	A	N	D	E	R
6	P	O	L	Y	H	E	D	R	A	L
7	C	O	N	N	E	C	T	I	O	N
8	W	O	O	D	P	E	C	K	E	R
9	U	L	T	R	A	C	H	N	S	A
10	D	A	S	W	I	R	E	S	A	E

Creamy stage indicator	SCOOP		Filibuster strategy	NOISE
Rust, e.g.	OXIDE		Passwords word	ABOUT
Silk substitute	NYLON		Gave the letters of	SPELT
Spots of land	ISLES		Sports venue	ARENA
With 7 across, module	CHECK		With Checkout, module	CHEAP
With 4 across, module	WIRES		$11.37 item	SUGAR
Lizard’s meal	PAPER		Bar game	DARTS
Fashion	TREND		Passwords word	LEARN
Terse	PITHY		Passwords word	WOULD
$3.25 item	CHIPS		Sea Shells word	LLAMA

CONSCIENTIOUSNESS