It seems like a pretty straightforward update.  I'd be doing roughly the same if I owned Lab 5s.

I actually have a ddrc-24 on my workbench right now.  I'm building a PowerLink interface for it so I can put it inline between my Moments/Essences and my speakers.  The Dirac room correction is fantastic (as tested from my PC) so I'm really looking forward to having it on all my speakers within the B&O environment.

A very interesting idea of which I started to explore with some equipment I bought after Steve's (Sounds Heavenly) film on his channel. 
The development B&O has taken into the BL5 at that time must have been enormous, taken into account all the different variables, knowledge (software development) and measurements.

It will be a challenge to get it all inside the BL5 with the lowest level of DIY and personal preferences , if it has to be applicable for the rest of the BL5 owners. 

I remember the time in the late 80's that I designed (Orcad-Ultiboard-etc) my own PSU to drive amplifiers used in Home based amplifiers (+ en - 40V driven STK modules). All in one cabinet at the end and placed inside the car. Worked. Very rewarding I can say. Designing, building, applying and using.

The acoustic engineering has been done for us by B&O, the cabinet is built for us and we do not need to worry about the production of the cabinet. also the cross over frequencies are known so we can copy those as well.

we probably do not know hte different output levels needed to equalize the 4 chassis’s and we will lose the adaptive bass but the Dirac software will solve this for us and proabbly much better.

the termal protection is probably more difficult but also not nessecary.

The diy MiniDSP kit is slightly smaller than an Ice module and runs on 12v. the 12v is also needed for the Ice module so this is available on the onboard power supply.

It looks like there is space for an extra Ice power on the side of the mainboard:

This looks great!

I’d be happy to offer my expertise as an Electrical Engineer.  I just need someone to donate a set of BL5’s to me so I have speakers to work with. 😂

For now i chose to have mine fitted with a refurbished B&O main chassis but they were doing that i learned that this project might be easier than I originally thought. Some more I learned and just writing it down here for future reference

Crossover frequencies are: 120/600/2000hz

Cables could be reused from the original main chassis, but all cables and connecters are unique per speaker, this make the repair idiot proof.
It the 2 smallest ICE power units are replace le separate from the main chassis, I think they are normal std 250w ice units. If one of the amps fro the midrange or the tweeter is broken this is repairable in my opinion.

Looking a 2nd time at the icepower site the BL5 main chassis might be build out of the Stock icepower ASP1000 added onto that one Icepower 1000a and 2 Icepower 250a (the asp contains the power supply. (635€ combine) added to that you have the DSP unit some cooling, cables and mechanical construction to combine all of that. 
the repair price was 925 per speaker so I think that is actually quite reasonable for the DSP part and the work done.