Custom and parts of prayer that are not obligatory

Hello Rabbi, I saw that the Rabbi answered two years ago someone who asked about parts of the prayer that are not obligatory, that indeed there are parts that are not obligatory, but the custom requires them. My question is – I have a very difficult time with the length of the verses of Dzimra and also some of the endings of the prayer that the Rabbi noted are not necessarily obligatory. The question is, is there really a complete obligation on the part of the tradition for everything and is it worth investing every effort on the subject and sweating over every chapter of the verses of Dzimra (of course, if this is the answer, that’s what I will do – or at least I will try as hard as I can…) or is it perhaps the obligation of the tradition for some of them less strong, or is it possible to make a vow waiver in this matter? Thank you very much!