My 1st 44 I ran at 5.0 and it was strong, but it only lasted a couple months, I did run it hard every day and I overheated it, that's why I go big on heat sinks now.
I have one that's been at 4.5a through 2 builds and is still strong and a double at 4.5 a and one more corrected at 4.5a
4.5 seems good, you could push to 4.75a but if you go 5.0 I would keep duty cycles short.
However they are very tough diodes.
If you can test your output and you don't see any fold back until like 5.75 then 5 amps is ok, but if fold back starts before 5.5 then I would stay under 5, simply because everything wears down and you need to leave a little room.
Even in the projectors over their 20k hour life they turn up the power to compensate, that is one reason they are not pushed to the max, also the higher you drive it the less efficient it is and that means more byproduct heat.
At 4.5 you should get a long service life, I have been doing well there.
Also you need good batteries, they make a real difference, the SXD minimum is 6.8 v under load, I have started running 3 cells because I am doing 2 diode builds.
The Efest IMR hold voltage under load well.
(jokes)
