yes adding perlite helps MG...MG is fine you just cant add nutes for quite a while. I use it and my plant looks decent ( im a 1st time grower not a pro ). You will get alot of MG hate tho.
dosn't miricle grow also includes metals: 0.38 percent arsenic i'd look for options without it . smoking arsenic will give you a twitch like a tweeker or so i'm told .