Any issues engraving a magnesium lower?
Also, it's factory cerakoted FDE. What's an easy color fill?

Have 2 FDE...very light....nailpolish works for lettering.  Only issue is slightly longer channels for trigger pins.  The last one included two pins....stock ones seem kinda short?

Ya, I have one fully built as a pistol now but after having stamped lowers, pistols are so gay. I had heard some chatter about the inability to engrave a magnesium lower...

I too am using the supplied oversized hammer pins with a mil-spec trigger

Nobody else thinks it's a bad idea to engrave?

If you want it, do it.

My brother in law had his engraved and was not very happy with the results. Not sure if it was the lower or the engraver.

Any other opinions before I take the plunge?

I have one built into a pistol with a 10.5" barrel. Build went smoothly and you can definitely feel that it's a little lighter.  The front lugs have scratched, but I'm not sure if that's the lower's fault or the fact that I have it mated to an upper with a Seekins MCSR rail, which has an edge to it.  Overall, I like the lower and wish I could pick up their previously produced upper, but it seems to be MIA. I also have an unbuilt FDE lower I've been thinking about building into a dedicated .22.  I would say go for it if you like the design and weight, but don't pay more than $50 for it - that's what I paid and they occasionally drop that low.  If I were going to SBR, I'd get a plain-Jane forged lower, preferably something with no goofy roll marks. Occasionally, Spikes does a run of no-logo lowers.

This is mine. I think it was $65-70 last year or so.
It's a lightweight 762x39, 12.5"

I've got other SBR'd lowers but was curious if this would work too.