I only thought of this topic because it sounds a bit daunting a subject; but it need not be at all.
Another reason to put the topic out is because I had to do a lot of this when I got my first concertina, transposing music to fit into suitable key range. And now, more recently, I acquired a wooden Chalumeau ( early form of clarnet) with a simple chromatic octave, and so again my transposing skills are required again.
I do not see it as a burden having to do this, indeed it is a good skill to have, all you have to do is keep your eye on taking the tune up, or perhaps, down the number of steps in interval to fit. For example, you have tune in G major, needs to be used as F major.. just count down the one place ( in this example) and ensure you have made all the notes to follow suit. (And add the appropriate key signature).
Using what I call transpositional instruments, that require a lot of adjustments, may be seen as making more work than needed. But I think that you often gradually build up a unique set of tunes unique to the need, as required, and often pieces that may not be used normally, or even overlooked in their home key.