I don't think Steve is misinformed, I think he is taking the "safe" route...and passing that info (Dreamline need some real user testing, like for 3 to 6 month to know it, is like DO NOT DRY FIRE your impact...I do this every time I clean the barrel and CERO issues... if you know what I mean)
IMO Dreamline is what it is, a highly customize pellet airgun for $1.000, con it push slugs at good speeds? I believe they do (light ones) after buying a slug liner and a bit of tweaking but are not designed for slugs. I Haven't seen a good accuracy Slug review yet only hunting videos (good ones, but for hunt 2 or even 3 MOA Accuracy is good sometimes), and the guys from SA Airhunters make a nice attempt, but need more (IMO)... probably due de lack or stock on slug liners ... hope will see soon someone do in it... soon, including different speeds.
I believe Dreamline needs more time in the market so shooters can tweak it more. Also slugs needs more test, some are heavy and need Power Kits even for the impact (if a power kit is needed for the impact ... for the dreamline what to expect?), others are light but no slug liners for those available to general public yet (0.25 Slug liner 700mm for example) ... Slug shooting is in development still, and I believe this year will see good things and in 2020 even better, the problem is that maybe (just maybe) politics will chime in (as they might in semi autos or autos) and that will suck ... will see