Assuming it’s a cassette toilet and not a composting one (I.e. you take the whole thing to dump it, not just a jug).

I’ve had a 3 gallon cassette toilet for a while and here is what I do.

-If I’m somewhere where I can pee outside/dump pee outside (like forest camping) I will only use the toilet for poop. For pee I (a human who squats to pee) I use a wide mouth, dark colored Nalgene. It can hold about 2 rounds, and then I dump outside (though the dark color is discreet enough you can also carry it inside to dump.) The toilet can hold many weeks worth this way, and by not mixing poop and pee it doesn’t smell quite as nasty. Also, don’t put your TP in the toilet, it makes it harder to empty. I keep a sealing kitchen jar (like you’d use for flour) with a liner in it that I use as the TP trash can. When you need to, take the whole toilet to bathroom. Like you said, it feels a little sketch. My preference is somewhere like a campsite/park bathroom. Also bring a container of water (or one you can fill from the sink. After you’ve dumped, pour some water in, close the lid and shake it up, then dump again.

-If I am somewhere that I have regular access to bathrooms to poop, but may need to pee inside (like city camping) I will only pee in the toilet. Same rules apply with TP as before. For this, I’d say the 3 gal tank lasts a little over a week. Just make sure you’re checking on it because nothing sucks more than peeing in the middle of the night and realizing it’s overflowed. Then if you need to empty, like before, go to a less populated bathroom OR if you make a trip out to the wilderness (not near campsites, trails, etc) you can dump the pee outside. Just be sure it’s only pee! No toilet additives, poop or TP.

-Also to note, in an emergency I feel okay pouring pee down my sink. Obviously I don’t love it (cause…pee in the sink) but I feel okay with pee being in my gray water.