Let us know how it goes.
Being a fleet driver, I can already attest that not all injector mods are worth their salts.
In fact, they can make the MPG crash due to the amount of fuel they're capable of pushing into the cylinder and the results you get back out of it are two different things.
Automatic and a power mod give you only so much - the Manual might give you a little more but the overall end result is more of a need to make oil changes and fuel stops to make it thru the years you own it.
If you race - that is one thing, but if you commute or work as some sort of UBER - Dash or Taxi - the cost of fuel to keep it running gets pretty stiff on the wallet and ledger sheets
Currently working in one now, that if the wind blows in the right direction - you can get the rich rotten egg smell from the catalytic converter trying to clean up the exhaust - just a reminder that it's running rich as you're stuck in stop-start traffic trying to make someone happy delivering what they need to make their stuff work right.
I'm in a position where I see the results of bad decisions of the behalf of previous owners - and see the relief from the current ones knowing it can get fixed right so they can have a car that works again.
So unless you have the $$$ to do the upgrade - you'll also need to do the tune, the upgrade alone usually is not worth it. The fuel trim the system attempts to make usually sets the MIL light as it's trying to tell you it doesn't like the new setup.
With the Fiesta no longer being made, it's a relic, so to just throw money and parts trying to get more from it is not worth the replacement cost. For you may not like the lengths, jumps and hoops you may have to go thru to get another car to mod.
You may not have wanted to hear that, but the Fossil fuel era is going away, people are also being led to believe that one is better than the other and the other side of that coin is saying the same thing for their side with the rejoinder that it takes longer to recharge than it takes to just fill up a tank and be on your way.
When you're in an emergency...you don't have time to use an extension cord...

We're being forced into a direction - whether we like it or not. Until the up-front costs of owning up to their recommended upgrade to the family car, my approach is to preserve that which you have - until that time comes where the switchover - or our end times - is easier to accept the outcome.
Another thing you're going to find, is the level of mod tunes you can acheive is less in the later model years, so if you trash the 2014 - a 2018-2020 year mod is going to be harder to acheive - they locked up the PCM pretty tight - so you're also stuck with a range of years and the parts for them, you can possibly work with - Ford learns from their mistakes.
It's your choice in life, I learned hard lessons thru the years to preserve what I've invested in - it's not worth jumping ship or trying to make a canoe into a sailboat - one requires a strong swimmer and the other needs a keel to keep it upright - either way you'll need to add more in parts, labor and it's cost, to obtain it.
Don't worry, we're on your side, we get it. We just can't offer good solutions for mo' powah - power delivery options except to get rid of it and buy the Ferrari...
...You can not push start a Tesla, it'll take several miles of towing it on all its wheel to even charge it enough to (hopefully) make it to a place to plug it in....