Without battens any mainsail is truly hampered holding any decent shape in the leech area and the ability to adjust and hold the draft at any specific location fore and aft is also compromised. Furling masts exclude the use of horizional battens and thus vertical battens came about.
Newer sail designs deal with this much better and the higher quality lofts have many improvements to corredt this problem, but they come with higher prices.
Does your sail have batten pockets in place or is it entirely without them? It they have the pockets then by all means install battens. If not, consult your local loft about their opinion on installing them if the sail is not already structured of operate without battens.
If this is your first boat or if you are new to sailing then your local loft can give you opinions about learning to use the boat without then until you are experenced enough to require this structure.
Enjoy your boat and use it every chance you get.
Ray