I had a really bad off on my hybrid (essentially the same as the roadrat) when I first got it. I tried for about a week on the commute to manual and wheelie it with the same technique as my MTB but got frustrated. I ended up getting a little more aggressive with the technique and found that when you finally find the balancing point it really requires fineness and feathering of the brake.
Sadly my V-brake was appalling and I got caught out. I fell straight onto my arm with the bike and body (first thing to make contact) and I was still clipped in. It didn’t break the skin, but left the most horrific bruise and it’s still left a scar, plus the hair wont grow back in that spot, after 4 years.
I can now wheelie road bikes comfortably, but just we aware that it can go wrong much quicker than on an MTB.