It can but likely to run into issues.
Personally I would say its not really worth flashing.
Its a risk the fps difference is likely not to make a difference that one can tell.
I have samsung hbm on my vega56 but I wont flash it.
I may do it if I watercool it one day but not sure I do it then anyway.
Games I play runs great anyhow
As I understand it, the risk with Samsung HBM is almost nil as long as you get the right BIOS for your board (i.e. reference, nano, etc.).
So far I've managed to create two profiles that are at least Time Spy stable. Both use stock core clocks:
P6: 1050 mV, 1537 MHz
P7: 1100 mV, 1592 MHz
HBM: 950 MHz
Power Limit: +50%
GPU Score: 7015 (+8.5% compared to stock)
Peak Sustained Core Clock: 1570 MHz
Peak Sustained Power Usage: 205W
P6: 1000 mV, 1537 MHz
P7: 1050 mV, 1592 MHz
HBM: 950 MHz
Power Limit: +50%
GPU Score: 6951 (+7.5% compared to stock)
Peak Sustained Core Clock: 1555 MHz
Peak Sustained Power Usage: 180 W
Losing 1% performance whilst saving 25 W seems like a good deal to me. I might try pushing the HBM further but I reckon it's near its limit. Lowering the core voltage any further will just drop the core clocks so I don't think much improvement can be had there.
I don't seem to be able to set the fan on this Vega 56 Pulse between 0% and 50%, which is a bit annoying because the noise at 50% is definitely more than my RX 480 is at 50%. Temperatures are hovering in the low 60s during tests but I'm sure they'll go higher after an hour of gaming.
EDIT: 960 MHz HBM passes Time Spy too! 970 MHz causes crashes.