You have to read the notes on the massive dev chart. For this combination, it says:
Agitation: continuous first min, then 10 secs every 3 mins.
Moreover, massive dev chart times are to a large extent user-submitted, and those times are not verified in any way. So if someone at some point did 33 minutes with this combination, obtained absolutely bulletproof negatives that are virtually impossible to print, BUT they were happy with it, they could have submitted that time and it would end up on the chart just the same.
For unknown developer/film combinations, I generally try to approximate by picking some known film/dev combinations and then extrapolating from there. For instance, you're looking for Orwo UN54 times and Microdol-X. You might look at times of Orwo UN54 with more mundane developers, like D76. There's a D76 stock time of 5.5 minutes for this combination.
Then look at times for D76 for a film that you suspect is not too fundamentally different from the film you're about to use, and pick a film that also has times for your developer of choice. Given that UN54+ is a 100 speed panchromatic regular (non-T) grain film, you might use something like Foma 100 as a reference - although there's no Microdol 1+2 time for this (the 1+2 dilution appears to be super uncommon). D76 stock for Foma 100 time is 6-7 minutes; let's say 6.5 minutes, and Microdol stock is given as 8 minutes. So roughly 25% longer for Microdol.
Now take your D76 stock time for UN54 and add 25% to it, which will give a little less than 7 minutes; I'd round up to 7 minutes. That's for Microdol stock. You could approximate the more dilute variants by looking at Microdol times for other films and then working out an approximate multiplication factor. If you do that, you see that the difference between stock and 1+1 is usually something like +20% or so, and stock vs. 1+3 is maybe +75% or thereabouts. From this, you could infer that UN54 in Microdol 1+2 might work OK at roughly 10-11 minutes with regular agitation. That's what I'd start with.
I suspect the time of 33 minutes was submitted by someone who either likes their negatives bulletproof, who consistently develops at a lower temperature than 22C without realizing it, who underexposes their negatives and makes up for it during development etc. Or maybe it's just a typo and it should have been 13 minutes or so. Who's to say. As said, Massive Dev Chart times sometimes have to be taken with a grain of salt. Some triangulation as shown above can help to work out if there's something funny going on, and if that's the case, you know it's a good idea to do a clip/strip test to establish a starting point that works for you.
