In my experience as someone who often plays Trials with people who aren't as PvP-focused as I am, it actually boosts my KD if anything. More kills for me to secure when my teammates aren't as good at it. And this applies whether I'm playing with friends or solo queuing.

I'm like a decent 1.5 KD player in PvP generally but 1.75 lifetime Trials KD and this includes playing during the dark times of triple new gen console pool:

https://trials.report/report/1/4611686018430247198

As far as LFGing goes, I don't do it often, I'd rather lose with friendly people than play with high-strung LFGers, but I do have enough LFG experience to know the people you want to link up with from LFG are going to be smart enough to look past a single number like your lifetime KD. Anyone who views KD as a be-all end-all enough that they are going to cut people off because they are a 1.3 instead of a 1.6 is probably a clown that is going to dip out and project all of their own failures onto you the first time your team loses even when its to a team that your team had no statistical shot of winning against. Playing with people like that isn't worth anyone's time.