Yes you can write your own...
I sort of understand the logic flow of the options, and wrote new ones exactly the way you describe: substitute string content in those pesky mega strings that make them work...
Each option has the following event set:
[use 1775 USA buys supply as example]
evt_nam_USA_Repl_Supply_AIActivate
enables the option for the AI, with probability that AI "does it"
evt_nam_USA_Repl_Supply_ON
Activates the option in ledger
evt_nam_USA_Repl_Supply_Check
checks to see if player selected the option this turn, and if there are enough EP [also any other conditions you wish]. If all true, then "does it"
event includes the 'action' and text messages to notify both sides
event de-activates the option
evt_nam_USA_Repl_Supply_Regen
Reactivates the option, per the conditions.
This is where we limit the number of 'reactivations'...
All the 'non-option' event script can be used [probability, ownership of regions, counting units, etc.]. The 'ActorPool' just adds the ability for the play to choose to do it....
Lots of strings to add, logic to check. It only takes one small typo or string error to FUBARR the option. Trust me: been there, did that
Good luck! Advice freely given! Buy your own anti-acids