Significant exposure to the US turbine market. I don't have the statistics but the US turboprop fleet is massive. It probably dwarfs Australia by a massive factor (like 100 or 200:1).
Reverse effect of forex is great. All revenue generated by Prime, converted back to AUD is a massive benefit.
Prime were doing overflow work for PTB for years. Now that revenue is not lost by subcontracting the work out to a 'third party'. PTB retains both the top line revenue and the profit margin. The company has had a long working relationship with them, I don't think there is any really pressing need to have boots on the ground to oversea an already successful company.
Diversification point is huge, plus EASA/FAA certification opens markets beyond just North America.
As for the Cons, you raise valid points. I suspect that Prime directors will be contractually obligated to stay around for a reasonable time. Usually three years for transactions of this ilk and probably have enduring restraints for up to 5 years.
COVID 19 will have a short term effect. Aircraft will be used less but still require routine maintenance and calendar based overhauls.