Kid,
I don't know much about batteries but based on the posts of others, it seems the batteries you mentioned are ok and won't get damaged but also won't give the M43 max light output since internal resistance is too high on non-IMR batts. Generally speaking, the higher the capacity, the higher the resistance, is how things have turned out with battery technology . This also goes for IMR/Hybrids which have slightly higher internal resistance over regular IMR but not as high as your 3400 batts. Your 3400 batts have high internal resistance which slows the flow of current provided to your light's driver.
Also, the graph below (see link) shows that as the battery voltage goes down from 4.2v to 3.2v as it discharges, the IMR actually has higher capacity in that voltage range. The hi-cap 3400mAh you mentioned only comes into play as the battery runs down below 3.2v - which would be getting into lower power mode usage like low or moonlight mode as the batts run dry - not what the Octigon M43 was really meant for. On Med or hi or turbo, the 2500 mAh IMR would actually be in the greater capacity range. I don't know why this is so, but that is what the graph in the link below shows.
In other words, spending $180 on a light which works best on IMRs is worth spending the extra $32 for 4 IMR batts.
See the graph link below but remember to click on the 5A setting since the M43 is usually going to be running higher Amps - the lower 2A setting will show that the Panasonic 3400mAh batt gives better capacity in lower Amp usage than the LG IMR - but I assume this Noctigon light will be used on the higher amp settings, being a high power light and all.
Now, if that graph just had the option to click on 10 Amps, that would probably show an even greater battery capacity advantage for the IMR:
http://www.dampfakkus.de/akkuvergleich.php?akku1=507&akku2=141&akku3=0&akku4=0&akku5=0&akku6=0