Historically, I have mixed pelletized lime with my seeds and spread them that way. I'd divide the seed into equal parts. Divide the seed into 8 prts if i had 4 bags of lime. Then pour some lime in a box, put one part in, mix it a bit, then put the rest with the other 1/2 of the bag. Getting sick of the lime dust and extra work on multiple plots.
I used the same spreader. Not fun with lime added. Some folks mix small seed with sand or kitty litter. That spreader is too coarse for pure small seeds, like frost seeding clover. Atleast from my experience. I got a solo spreader and didnt like it at 1st, but it can frost seed by itself without additives.
Overall in small plots, set it as low as it can go, go north soth passes, then switch to east west pass. On my small clover plots, i sometimes do 3 passes until i get the amount of seed i wanted on there.
I have mixed seed with fertilizer and had good results many times. Everything I have planted has came up, but cant speak of germination rates. It's not good to mix seed with the nitrogen part of the fertilizer. Mixes oats and potash is very common practice in farming though. Everything I have planted this way has not sat for long. Maybe at most a week or two with clover and fertilizer, but I usually spread 6-24-24. LEt the clover make up for the 6....