I have one of Dlasks very early lowers and really the only issue is with Thermelts because of the bevel to the inside magwell. All else is gravy. Now, their newer model, has a bevel that is more accomodating to Thermolds.
If other mags aside from the Thermolds didn't work then, they are out of spec mags, period. I've seen them and tried them myself.
You'll run into the occasional mag that was pinned on the spine and the rivit was left protruding a bit much and this drags against the magwell spine making the magazine difficult to insert and extract.
The early Dlask receivers did have a smidge of a thicker (longer time in) anodizing, but if the parts you assembled with were within spec, they fit great. 99.9% of the time.
When a lower is newly manufactured it may have some imperfections, or excess anodizing in small areas where small parts fit. All pretty normal stuff. I'm pretty sure even a Colt receiver may have needed to be fit during assembly to a certain point to guarantee the reliability of the rifle.
After parts are fit properly, you can dissassemble, mix and match with other manufacture parts to your hearts content. Then it's LEGO time like most people expect of ARs.
When you buy a stripped lower and assume installation, you're somewhat expected to know how to recognize and correct small fit issues if they arise. Otherwise, a complete lower with LPK may be a better choice.
Installing substandard parts, or out of spec parts not knowing the difference until the gun doesn't work and then #####ing at the lower itself makes as much sense as hair on a bowling ball.
The CGN lower deal going on right now, I read that whichever supplier of the final receivers will be, I forget now, (Wolverine? Questar?) will sell assembled receivers with LPKs so that nobody can blame the receiver itself when substandard parts are intalled and don't work right.
Well, that's a great idea, but imagine if you coudn't buy any stripped receivers any more because manufacturers don't want the blame for what kitchen mechanics do and blame the company for.
Anyway, ...

all I'm saying is that Dlask lowers, from what I've seen and used for a number of years, are pretty good receivers and if you want a Canadian AR lower component. Call and speak with Josef at Dlask Arms Corp.