I hadn't come across dessicant humidifiers before - thanks for posting, simon.
My first thought is that it is important to assess whether the extraction rate of any particular model is sufficient for your workshop. I say that because the Ruby's published extraction rate is 5.1 to 5.5 Ltrs/day (depending on the temperature/humidity) which is on the low side compared with, say, the Mitsubishi compressor-type that I use in my cellar/basement (16 Ltrs/day).
By the way, I know you have ruled out compressor type dehumidifiers but my Mirsubishi is now 15 years old and still going strong. Mitsubishi dehumidifiers are significantly more expensive than most but they, seemingly, keep going for a great many years, are versatile, good looking and can continue operating after a power cut.
Hermanos Conde 1968, Stephen Frith 2007 "Guijoso", Christopher Dean 2018, Ana Maria Espinosa 2014