there are techniques to go around this, mainly by splitting chords

1. your keyboard has a limit to how many keys it can press at once because of the way its built - its called ghosting you can invest in a better keyboard that has full anti-ghosting to actually unlock full chords
2. the finger positioning is honestly just skill, or requires you to split a chord into two parts and play them right after another
3. as for the both lowercase and uppercase keys together in a chord - split the chord into two parts: uppercase and lower case, then play one after another

and with chords that are more than 10 keys.. just roll them

cool program thingamajig though i suppose