Some regulated mods can fire coil builds that are below 0.1 ohm, like, for example, DNA mods usually can, but on a DNA mod typically you'll find that the farther you go below 0.1 ohm the lower the maximum power that the mod is capable to deliver will be. It doesn't harm the mod or anything, as a regulated mod is designed to work reliably within the range that it's been designed to work in, or at least it should be, but the efficiency of the board inside the mod and the battery life resulting from that might be a little disappointing if you build your coil builds to such low resistances. Similarly, if the resistance is a bit higher than the range that is the recommended range for the regulated mod you're using the coil build on, then normally what will happen is the power output will gradually start to be throttled back by the mod way sooner than you might actually prefer, like, maybe it will start to happen when the batteries have gone down to 3.8 volts or 3.7 volts, instead of only after they've gone down to, say, 3.5 volts or 3.4 volts.
Especially if you are a high wattage vaper, vaping the batteries all the way down to 3.2 volts is something that tends to be not feasible because the "weak battery" message will appear so much earlier than that, but... in addition to that, the performance of the chip inside a regulated mod can also be held back by how the batteries themselves respond each time when you press the fire button so in fact the flavor and feel of the vape can also be ruined by choosing the wrong mod or the wrong batteries, or both, for what coils you had in mind. So much so, at the time when I moved from my Wismec Reuleaux RX2/3 with three Sony VTC5A batteries to my RX300 with four of these same batteries, I immediately noticed an incredible huge boost in the flavor performance I was getting from my coil build despite I was only vaping it at 140 watts and despite the RX2/3 using three batteries (and Firmware V4.13) is actually a 250 watts mod so I can't exactly blame the incredible huge difference on that. So the resistance can, and does, affect the performance as it affects the performance of your mod and batteries.