Looks like I'm using version 2.2 RC1 of Wiiflow, and the CFG Loader that I installed has the the filename Cfg_USB_Loader_70.zip.
I only downloaded the two recommended cIOS files (249dx56 and 250dx57) using ModMii, and at least CFG Loader seems to be utilizing them to load the games. I've manually tried both 249 and 250 through CFG.
Other than that, here's the syscheck output:
sysCheck v2.1.0b12 by Double_A and R2-D2199
...runs on IOS58 (rev 6176).
Region: NTSC-U
System Menu 4.3U (v513)
Homebrew Channel 1.0.8 running on IOS58
Hollywood v0x21
Console ID: 152320748
Boot2 v4
Found 88 titles.
Found 52 IOS on this console. 6 of them are stub.
IOS3 (rev 65280): Stub
IOS4 (rev 65280): Stub
IOS9 (rev 54321): Trucha Bug
IOS10 (rev 768): Stub
IOS11 (rev 54321): Trucha Bug
IOS12 (rev 526): No Patches
IOS13 (rev 1032): No Patches
IOS14 (rev 1032): No Patches
IOS15 (rev 1032): No Patches
IOS16 (rev 54321): Trucha Bug, ES Identify, Flash Access, NAND Access
IOS17 (rev 1032): No Patches
IOS20 (rev 54321): Trucha Bug
IOS21 (rev 1039): No Patches
IOS22 (rev 1294): No Patches
IOS28 (rev 1807): No Patches
IOS30 (rev 54321): Trucha Bug
IOS31 (rev 3608): No Patches
IOS33 (rev 3608): No Patches
IOS34 (rev 3608): No Patches
IOS35 (rev 3608): No Patches
IOS36 (rev 54321): Trucha Bug, ES Identify, NAND Access
IOS37 (rev 5663): No Patches
IOS38 (rev 4124): No Patches
IOS40 (rev 3072): Stub
IOS41 (rev 3607): No Patches
IOS43 (rev 3607): No Patches
IOS45 (rev 3607): No Patches
IOS46 (rev 3607): No Patches
IOS48 (rev 4124): No Patches
IOS50 (rev 54321): Trucha Bug
IOS51 (rev 4864): Stub
IOS52 (rev 5888): Stub
IOS53 (rev 5663): No Patches
IOS55 (rev 5663): No Patches
IOS56 (rev 5662): No Patches
IOS57 (rev 5919): No Patches
IOS58 (rev 6176): USB 2.0
IOS60 (rev 54321): Trucha Bug
IOS61 (rev 5662): No Patches
IOS70 (rev 54321): Trucha Bug
IOS80 (rev 54321): Trucha Bug
IOS90 (rev 54321): Trucha Bug
IOS202[60] (rev 65535, Info: hermes-v5.1): Trucha Bug, NAND Access, USB 2.0
IOS222[38] (rev 4, Info: hermes-v4.0): Trucha Bug, ES Identify, NAND Access, USB 2.0
IOS223[38] (rev 4, Info: hermes-v4.0): Trucha Bug, ES Identify, NAND Access, USB 2.0
IOS224[37] (rev 65535, Info: hermes-v5.1): Trucha Bug, NAND Access, USB 2.0
IOS236 (rev 54321): Trucha Bug, ES Identify, NAND Access
IOS247 (rev 65535): Trucha Bug, NAND Access, USB 2.0
IOS248 (rev 65535): Trucha Bug, NAND Access, USB 2.0
IOS249[56] (rev 21006, Info: d2x-v6): Trucha Bug, NAND Access, USB 2.0
IOS250[57] (rev 21006, Info: d2x-v6): Trucha Bug, NAND Access, USB 2.0
IOS254 (rev 65281): BootMii
BC v6
MIOS v65535
Report generated on 2011/08/16.