emergency: should i put this lumpy platy back into the main tank?

Hello! One of my first platies, which i have had for maybe 2 years now is looking weird, so I have separated him. He is eating well and is active. However he’s kind of lumpy which concerns me. I’m going to be going on vacation for 10 days, and only have a feeder in the main tank, wondering if i should just put him back?

If it is eating well and has been like that for a while, just leave it be.
If it became lumpy recently (in the last few months), it's probably still ok to stay there.
If it became lumpy in the last few weeks, move it out.

If he is already on his own and the tank doesn't contain any plants, put some plants in with him.