Val
To be accurate i fly the 737NG which has a very similar system to the T7
The whole purpose of VNAV is to allow you to fly stepped climbs/descents, but the MCP alt window is king and will not allow you to fly through it in either climb or descent, i understood the T7 was more or less identical in this respect?
What you can do is climb or descend away from the MCP alt with no protection.
So you could be flying along at 1200ft and select 10000 feet in the MCP alt window, this would open up V/S (vertical speed) mode, if you then dialled a positive rate of climb the aircraft would climb away from the MCP alt value with no protection the reverse is also true.
So starting at 12000 ft with 10000 in the MCP and with a +V/S of a 100ft/pm and say a thrust limited climb ceiling of 45000ft it would spend 5 hours 30 minutes slowly climbing, of course as more fuel was used it would be able to climb further and in theory would keep going until it could climb no more and the speed came back to almost min speed, i think? it would probably revert then to level change and with 10000 in the MCP alt window it might descent back there at idle thrust until it captured the 10000 alt (or a 100ft if that was selected?) and that could be below sea level if the QNH was low (1009 or less) with STD (1013) set on the sub scale .
They may be difference between the NG &T7 in the logic but you get the idea, if i get chance i'll try it in the sim.....