As I see it - the bar is a good safety feature to prevent the boat from sliding forwards if you crashed into something, with the winch holding down it heels the boat from sliding backwards.
That said, a steel bow stop with a roller or V in front of the bow eye stops the boat from going forwards, as does the V of carpet that cradles the front of the boat.
Any modification to your trailer should include: Bow stop - winch strap or cable and a good safety chain. I like to use a ratchet strap from the bow eye down/back as well.
Then of course you need rear ratchet straps to get your 3 points.
You never want to make your trailer "less" safe - but having occasionally had to trailer the boat with the bow strap not engaged because I could not get the trailer deep enough on a MI DNR ramp and was not allowed to use engine - I would say almost anything is safer.