"My beef with Epson is that carts and nozzles are separate"
That's a good thing; it reduces both running cost and waste. Designjets have been like that since they appeared, it is n't limited to Epson.
The issue is "if you don't use them for a while". The solution is obvious. You could even put in a cron job to print a test page every few days. Inkjets are more environmentally friendly than lasers, even if you print a couple of test pages a week.