Its all relative really. Doesnt matter if your in a PA44 which I all but 10 hours or a King Air. If you select a small enough field you will constrain yourself and machine.
If you are going to practice short filed take offs ensure you have all escape routes covered. Clearway, obstacle clearance etc. etc. Because if per chance you end up wallowing around at VMCA or under, you need a plan of action. No planning is lunacy!
Remmember because your in a twin doesnt mean an automatic out. It most certainly with no performance means a controlled ditching. My colleagues in my Company operate at high altitudes in the Mid Asian region in king Airs. Even at high altitudes in King Air Im talking 8000 elevation airstrips, an engine failure on take off usually incorporates a ditching unless in excess of a V2 speed is achieved.
So what Ive mentioned above comes down to one letter "P" for performance. If you have "P" alls well then good but if you dont, alterior plans need to be made.
P for performance ladies and gentlemen has the last word. Recognising its demise or increase quickly is the key to survival.
my 2 cents worth
Sheep
P.S. If it aint in the book dont do it. Why? Because it aint documented means it aint been researched, which means insurance companies aint going to listen to your excuse.