So I figured out a simple way to convert and then use IPS patches for the MAKEHACK Method that is ridiculously easy, currently I have only tried using the free range patch for FE8 with this method, but it should work with every other IPS patch, here are the requirements:
A clean GBA ROM. I will not tell you where to find one of these go Google it
An IPS patcher, you can find an IPS patcher on the internet go Google it.
An IPS patch (as stated before I used the FE8 Free Range patch, it worked but any other patch should work).
A way to make an UPS patch from a rom (such as NUPS).
A way to convert an UPS patch into a .event file (such as CUPS).
Edit taken from P33RL355:
So you would basically:
Step 1: Patch your .ips file to your ROM.
Step 2: Create a .ups file from that ROM using NUPS.
Step 3: Run CUPS to make a .event file from the .ups file.
And you can finally #include it in your buildfile.
But if you want it in more detail:
So after you have all that, before doing this double backup your ROM if you haven’t already (I will not be responsible if you lose hours weeks or even months of hard work if you fail to follow this step), after that go ahead and patch your ROM with the IPS patch using your IPS patcher, then use a program to create a UPS patch, I use NUPS, (if you use a different program you will have to figure out how to replicate this process) so in NUPS you will need to create a UPS patch from your patched ROM, to do this open NUPS then click “Create a new UPS patch” it will ask for: The Original file, point it to your original GBA Fire Emblem ROM and open it, your edited file, meaning the file you recently patched with your IPS patch navigate to it and open it, and the New UPS file, that will be the name of the UPS patch, you can name it whatever you want but I recommend naming it the same as the IPS patch you used, then click Create Patch, after waiting it should say “Patch has been created.” So now we can move on to our final step, move your UPS patch to where your “UPS to .Event” program is, I use CUPS, (if you use a different program, again you will have to figure out how to replicate this process) so just slide your UPS patch that you got from NUPS on to CUPS and it will ask for your clean GBA ROM navigate to it and open it, aaaaand bam, you will have created a .EVENT file from your IPS file, all you need to do after that is include it into your ROM Buildfile or include it from wherever else you want and use it, cheers!