As a rule, I would say no. Check this thread, it has some charts with efficiency and other data for a few boost drivers: Buck and Boost Drivers, Testing, Modding, and Discussion
The driver adjusts its output voltage by sensing the output current flow or current flow to the emitter. For this to happen the current goes through a sense resistor, usually a very low value power resistor located just before the negative output wire. Because current times resistance is voltage, this voltage drop at the sense resistor terminals is amplified and sent to the microcontroller. This is the way the microcontroller “senses” the output current and thus knows if the current flow is correct for any mode, and when not it either raises or lowers the output voltage. This is done at a very rapid pace, probably thousands of times per second although in this respect thefreeman can provide more accurate information.
Since buck drivers can only reduce the output voltage, not raise it, when the led requires an output voltage which is too close to the input voltage or even higher, the led won't receive the full current. This happens at some point as the battery is discharged and its voltage drops.
What do you mean with spms? Closest abbreviation to it I know is smps, for switch mode power supply… :D
I have a few of these buck modules. They are CC/CV DC-DC converters. You set them up by adjusting their potentiometers. Whatever voltage you set them at with their CV or constant voltage potentiometer will be the output voltage or maximum output voltage. When you don't need or don't want current regulation at all, you set the CC or constant current potentiometer all the way it goes (clockwise rotated, in my experience), this way you'll always see the full output voltage until the module protects itself because of some overcurrent or overheating problem. If you adjust the CC potentiometer and set some output current (connecting the leads from a multimeter in amperimeter mode is a way to see the output current, for example, at least if output voltage isn't too small), the module will reduce the output voltage if it senses that the output current is beyond the set value.
These modules are nice, I have a few at home, but because of the parts they use for current regulation (the onboard operational amplifier -LM358?- and linear voltage regulator, I guess) the will only work in CC or constant current mode if the input voltage is beyond a certain thresold, 6ish volts, close to 6.5V if I recall correctly. For this reason they cannot work in CC mode when fed with a 5V supply. This also happens in other similar DC-DC converters like the LM2577S-ADJ CC/CV SEPIC module (A.K.A. LM2577 CC/CV boost buck converter), and somewhat sucks.
P.S.: I would swap the current sense resistor in the Convoy 8A buck driver, with a 18mΩ (R018) for example the maximum output current would be 4.4̅4̅4̅A.