Yes, there's no recompiling that can be done anyway if you only have the binary and no source code. Writing the new machine code would overwrite some code at the start of the function you're modifying, but that doesn't matter if you just want the function to return true or false.
You could edit the binary manually with a hex editor, but some disassemblers like Hopper have a feature where you can type new instructions in assembly and it will assemble and insert them for you. I'm sure IDA pro has something like that as well.
IDA Pro as of 6.9 wasn't designed to act as a hex editor as such it's not the "ideal" but there are tons of scripts[1] that people use[2] to craft it into whatever you want. Likewise, it wasn't really a dynamic analysis tool but the healthy ecosystem kes it feel sorta-kinda powerful with the proper tooling + WinDBG. I'm using a fairly old setup (old dog, new tricks and all that - I stuck with SoftICE as long as I could) so there are likely better solutions out there.
[1] https://github.com/iphelix/ida-patcher/blob/master/idapatche... is what I have in my scripts dir, but I'm sure there are dozens of others out there. That specific Python script has the added benefit of being really approachable for the average user. Check Woodmann or Github or wherever people post their scripts these days if it doesn't meet your needs.
[2] IDA's basically turned into emacs, where the real power comes from all of the tooling you can conf into it. A stock 6.9 + HexRays license is worth it just for the free tooling you can find.
You could edit the binary manually with a hex editor, but some disassemblers like Hopper have a feature where you can type new instructions in assembly and it will assemble and insert them for you. I'm sure IDA pro has something like that as well.