well, i have just explained to you how to flash it without using fastboot commands,so im not sure why youre confused
the wire trick should have returned you to a
locked status. most folks wish to keep it that way,in case they need to return their devices for some sort of warranty claim.
even if you are s-off,re-unlocking your bootloader leaves the watermark that the good folks at sprint or htc can see. they will know,if they care to look, that you have unlocked it at some point,as when you re-lock it,you will be
relocked. listen carefully to this next part,if you have an evo3d with factory warranty that you do not want to jeopardize:
if you unlock with htcdev after s-off,you cannot get your hboot banner to say locked again,unless you turn s back to on,and then do the wire trick and s-off again.
having said that,if your device has no factory warranty,or you just plain do not care,then unlocking so you can use
fastboot flash is certainly an option.(i actually keep my rezound hboot
unlocked,but i bought it used and do not care.)
i put together a download for you,and gave you instructions to flash it,becasue:
1)you said you had trouble with
fastboot flash previously.
2)you said you prefered ext 4 recovery.
if you wish to unlock and fastboot flash a recovery,you can,but do so haveing read the above warnings about the locked/unlocked/relocked banner. you can fastboot flash twrp,or you can extract the download i linked for you,and fastboot flash ext 4 by moving the recovery image to you adb/fastboot folder. its entirely up to you.