Combining your trials and freestyle unicycle into one machine has the same problems that any multi purpose unicycle has. You are making compromises to produce a unicycle that is suitable for both purposes.
An “ideal” trials unicycle is not ever going to be an ideal freestyle unicycle and vice versa. That being said, for many people combining your trials and freestyle machine makes a lot of sense. Not everyone wants to be world class in both styles of riding.
The freestyle unicycles ridden by world champions have a 20"x1.75" tyre, 102 or 125mm cranks, Miyata style seats (some prefer no handle), rubber pedals, a long seat post and a frame suitable for resting your foot on, with small tyre clearance.
The trials unicycles ridden by worlds champions have a 20"x2.5" Monty style tyre, 140mm cranks, splined hub, Miyata style seats, metal bmx sytle pedals and a frame with large tyre clearance.
This means your compromises are going to be in the following areas: the tyre, cranks, pedals and frame clearance.
The thing to remember is that while a freestyle uni is ideal for most freestyle tricks it will only stand up to light trials use. A trials uni is built to be bomb proof and while some of the advanced freestyle tricks become harder, they are probably still doable on a Tuni.
If you want to do hard core trials AND reach level 10 I would suggest buying both types of unicycle.
If you want to do 6 foot drops, huge gaps, ride rails and the occasional outdoor freestyle session buy just a trials unicycle.
If you are not sure which way you are going to go, buy a Monty wheel, with 125mm cranks and plastic bmx style pedals. This is a good compromise between freestyle machine and trials unicycle. They aren’t too expensive and you can always sell it later if you decide to focus on a particular style of riding. Note that some gymnasiums won’t be happy with your riding a Monty tyre inside as they tend to mark the floors.
If you aren’t ever going to do much more than 1ft drops and want to focus on freestyle, buy a freestyle unicycle. (That being said I did 3 foot drops on my freestyle uni and could jump up 2 feet - did bend my cranks lots though).