I can't help you here but will be following this thread. I will be upgrading from the distributor to a 24x ignition in my 98 5.7L when we're out of winter (I have all the parts) and contacted them about their tuning. First email sent 1/3. They replied on 1/18 and didn't seem to have even read it. It was just a canned reply repeating options and cost that was already posted on their website. In my case I need a generic tune before I run the truck and then a tune after and that isn't clearly covered. I was going to write them off but decided to try again so on 2/3 I replied to their reply again asking how it would work, what option to select, and again long delay. I contacted a local shop about dyno tuning in the meantime and they were familiar with it (said it's popular with local hot rodders which ain't me, I'm just looking to modernize). Blackbear finally responded on 3/2 that they could do it. I was back to thinking I would use them because of they're familiarity with the platform and reviews. But based on your post now it looks like they may pull the disappearing act so back to local tune (I'll still do the work and have it towed to the shop, the shop doesn't have a bench harness so the truck needs to be there in whole, not just the pcm). Maybe someone else can reply with a RECENT positive experience but I doubt at this point that I'll risk using them. Wish you luck.
Note that I contacted Lew at Diablew during this and he replied immediately. He won't do anything more than mildly modified builds that have a pcm that can be tuned by HPtuners. I have a 411 pcm which is capable but he said he won't tune the 411/5.7L combination. Not a hit on him at all. He was quick to respond and clearly addressed my question so I wish I could use his service. Just wanted to let you know that Diablew (most likely) won't be able to help you. But if you ask you'll get an answer within a day.