Use a Transfer Behaviour effect to copy the buffs on the old units to the newly created ones before destroying them.
The Transfer Behavior effect works. Just to explain here what i have done:
I have added a Set effect with the Modify Unit effect and a Create Persistent effect with a Period Count of 15, the Period and Initial Effect fields have the Transfer Behavior effect and the Target: Location to Target Unit. The Create Persistent effect is there, because the Transfer Behavior effect copies a random behavior and not every single one. The high period count is to ensure that all behaviors are actually copied, because if the period count is too low, the CP will be inconsistent with the copying.
As of the Transfer Behavior effect i set the Effect: Count to -1, Effect : Copy to true, Target: Impact Unit to Target and Target: Launch Unit effect reference to the create unit effect.
Else use a Use Calldown effect to directly unload your units without having to clone them.
The reason i want to do the ability this way, is because there doesn't seem to be a way for the Use Calldown effect to unload units only from the caster and not from other units of the same unit type as the caster. To clarify the caster has both the transport and the drop-pod ability.
Anyway thanks for the help. Now the autocast issue is left, but as i said at the beginning i don't really care if i ever manage to resolve it.
As of right now i have a functional drop-pod ability, that removes all units within a transport and creates a copy of them at target location.
The only problem is that the copied units do not retain any behaviors that may be applied to them like Plague (the effect that i use for testing). In addition abilities with autocast setting are reset to default and control groups are also not retained.
I want the gained behaviors to be applied to the copied units at least.
Here is the order of effects:
Create Persistent For Drop Pod Model
Iterate Transport to remove each cargo unit and create a copy unit at target location
A set with:
The create unit effect to copy cargo units and apply the following spawn effect
Modify Unit, that currently copies only vitals and kill count.