We never said that was impossible, we just said it's "much" work.
IPF can store whatever data you want, even RAW, which we don't want, hence we don't (publically) support it. Anyone could add transport layers to the decoder library (the source is available for some time now), so these formats could be transported properly (=without trickery).
But with the burden of checking every single dump out of the way, we can finally focus on such things (adding those little oddities), while others can just share and create the scripts which make use of the underlying technology. IFW has already confirmed the support of these.
Just to put things into perspective: These Psygnosis games do not use proper MFM, hence the need for a new transport layer. Such edge cases affect 0.3% of software out there. IPF was designed with such challenges in mind, but that does not mean it does not require manpower. IPF is just the container, like MOV, MKV or AVI, with separate encoders (think of video codecs), like MPEG2 and H.264, handling the actual data.