That's a pretty tight radius, but I'd try it. Why not. I've bent a lot of wood for bows with steam, boiling, and with a heat gun... hundreds of times. I've never done it by soaking it and then microwaving it, but wouldn't rule that out. That would be my last option only because I'm not familiar with it.
A thin piece like that could be steamed over a pot of boiling water, or boiled right in the water, for just a few minutes and be ready to go. I do love my heat gun though, and use it for most of my bending, but when I have to make a tight radius, steaming or boiling raises the odds.
Success though will depend as much on other factors as it will which technique you use. Unless I had plenty, I'd hold back on my valuable piece and would make several test pieces of wood of similar species and grain structure, and try various directions of grain, methods, and forms until I found the combo that worked best.
Yes, Shifty is correct... 1 hr per inch of thickness is a good estimate.
Do a few dry runs so you know you'll be all set, and be ready when it comes out. When removed from the heat source, it cools quickly, especially a 1/8" piece, so don't play around. You'll have about 15 seconds. Elm is pretty tough, has interlocking grain, and takes heat bending fairly well, but I wouldn't bother shaping it much until the bend was made. Often, a piece can be heated and bent a few times if it doesn't go far enough the first time.
Oh yeah, and remember... heated and bent wood springs back a little when unclamped, so go about 4-5% farther than your target bend.
And leave it clamped until you're sure it's cooled throughout. Until cool and dry is even better... the next day, or two, won't hurt.