First off, just want to say Bloom are an excellent store to do business with and I wouldn't hesitate to recommend them. Absolutely no issue with the purchase process or their service (fantastic as always).
I should have done my due diligence prior to purchasing these. Unlike the 3.5 and 2.5 mm IFI iematch (both of which are balanced), these feature a higher ~ 4 ohm output impedance (compared to less than 0.9 ohms).
Given the sole use of the iematch is for ultra senstive, low impedance IEMs, having a 4 ohm output impedance is an incomprehensible design decision. On my Thieaudio V16, there is notable underdamping with audible degradation in the resulting frequency response.
Great idea, and ifi generally are great, but avoid this 4.4 model and get either the 3.5 or 2.5 ifi options (both balanced too!).
Really indispensable for pairing low resistance iem with the Diablo. Cost is very reasonable.