MSB for (very) long term?

Hi everybody. I'm at a crossroads contemplating two main paths of digital source upgrade from my Accuphase DP550: a used MSB Analog Dac with upgraded power supply or a used Accuphase DP-720 player (or perhaps the similar Accuphase DC-37 dac). This is all about the DACs, the CD player side is really not important.

Now, I'm not here to ask for a recommendation based on the sound quality but rather to inquire about the long term safety of going the MSB route, a company I'm not familiar with at all (apart from knowing they are truly high end and very expensive). Imagine you would be buying something for a very long term, say, 25+ years. I'm obviously aware that no one can predict the future, much less such a distant one, but please, bear with me and share with me your experiences and informed opinions on matters such as:

- can I expect the MSB Analog Dac to be supported in terms of software (Windows drivers and whatnot) for a very long time? Did MSB ever stop supporting an older product?

- the same question but on the topic of physical servicing the unit, spare parts availability etc. - for example, Accuphase are known for storing spare parts for very long periods of time

- are MSB known for their excellent customer support, like the Pass company is for example? (I had a very telling email exchange once with someone from Pass, hats off!)

- are the MSB dacs as reliable as they are expensive (or as reliable as Accuphase)?

- have you had connectivity isues with MSB dacs like unstable drivers or the USB not recognized by the streamer / PC?

Many thanks!