It's been done before by Ritter:
Urushibara Style Amphetamine
(
https://www.thevespiary.org/rhodium/Rhodium/chemistry/amph.urushibara.html)
Amphetamine can not be reduced any further by Urushibara Nickel, at least not under the above conditions, so overreduction is not a problem (BTW, how did you arrive at the abbreviation PN2P?).
Alcohol and water are usually fully miscible, but if there are
lots of salts dissolved in the water, a majority of the alcohol may separate and float on top of the aqueous salt solution. The alcoholic layer will contain almost all of the amphetamine at basic pH's, but you will ensure higher yields and a much purer product by working up as follows:
Extract the aqueous layer with diethyl ether (or equivalent) after decanting the alcoholic layer, mix it with the extract and evaporate the solvents. Dissolve the residue in 100 mL 5% HCl, wash once with 25 mL ether (discard), basify with aqueous NaOH and extract the amphetamine freebase with 3x20 mL ether, dry the solution over a little anhydrous MgSO
4, filter and evaporate to get relatively pure amphetamine freebase.
Crystallize by making either the sulfate, phosphate or oxalate salt as described elsewhere, as the hydrochloride is so deliquescent (hygroscopic) that it's almost uncrystallizable, and it won't keep in air.