Tweaking it sounds sensible. My DD HATED tummy time, she wouldn’t tolerate it at all at that age. I made sure she had lots of time held upright so that she could be turning her head, strengthening core muscles etc. We also did some other things to give her the chance to strengthen muscles - have you tried different positions. Sometimes I would lie on my back with my knees into my chest with DD lying along my shins while I held her arms and made flying noises. My DM also suggested just carrying her in lots of different positions so that she would strengthen different muscles e.g. sometimes picking her up lying across my forearms, or held sort of diagonally so that she would use her neck muscles. Also when lying on back putting a mirror just out of reach so she’d look towards it, and then moving it to the other side so she was doing lots of head turning. As she got bigger, she’d twist her body towards it a bit too, which eventually turned into rolling.
DD never did do much crawling. Maybe for a week or so - she learned to pull up and cruise, and then she found that a motivation to crawl so she could get to the sofa to pull up. But then she was walking a bit after a couple of weeks, so gave up on the crawling all together!
She’s 3 now. Always been great on verbal/cognitive milestones. She’s very gentle and not at all boisterous, so not as good at physical milestones as some others her age e.g. she’s ok on her balance bike, but not amazing, she can’t hold her weight hanging from a bar, but she can hop, run etc.
Basically I don’t think it’s made much of a difference that she did almost no proper tummy time. There are plenty of other ways of keeping a baby entertained and giving them opportunities to use their bodies.