Inclined thrust was tried on this craft (picture attached) an interesting feature was it compressed the craft which mean't when you throttled back the reduction in friction then causes the craft to accelerate which then makes the handling like nothing you have ever driven!
As many have experienced, when you apply the thrust, the nose will want to go down. This is because the thrust is applied at the center of the prop/fan, known as the thrust line. As the thrust line is above the rest of the craft, on a 'moment arm', at produces a nose-down 'moment' (or torque) on the whole craft. This isn't great, as it upsets our carefully balanced craft. Higher thrust line = bigger issue
There are several ways to deal with this problem, and one way is to incline the thrust line so that it passes through the center of gravity (bit of a simplification but close enough). What this does, as Derek points out, is generate another undesirable fact - we now are using some of our precious thrust just to compress the cushion. Not great!
Other ways to deal with the problem (you'll recognise most of these):
1 - Trim the craft 'nose up' when static - most smaller craft. Essentially a compromise - the amount of nose-up trim is right only for one speed (or acceleration). Eg Flying Fish.
2 - Fit elevators. These do the same as the inclined thrust line by deflecting the airflow upwards, but are probably more efficient being right at the extreme stern of the craft. And they are adjustable, so can be set for any given cruise condition. Eg Osprey 5 & many others
3 - Fit a cushion divider. This works by responding the the nose-down by increasing the cushion pressure in the front compartment to balance the nose-down moment. Eg all sevs, SRN4.
Cheers
Ian