When you see flowers forming on all the plants up Fertilizer to 50%. The pic of the plant looks really good and healthy. It has plenty trichomes (hairs) which is excellent. It doesn’t look like it needs to go to 50% yet. It will when all the plants firm flowers then tomatoes.
What you should do is self pollinate any flowers you see that are open usually mid morning to midday. You can do it 2 ways either by slightly tapping on the stem the flower is forming on or by using a battery operated toothbrush and let it vibrate the stem. Here’s an amazing slo-mo video of the pollen that comes out of the flowers. That flower is pollinated.
https://www.youtube.com/watch?v=eFzyIi6yn8Q
I would start putting a little bit of pure epsom salt in with the
nutrients. First mix the miracle grow ph the water let run thru the system wait 1 hour. Add small amount of pure epsom salt in a bottle of warm water let desolve add to reservoir ph the water. This will make plants bloom lots of flowers and as tomatoes grow add 1 time each month will make the tomatoes taste amazing!
Can your neighbor send you pics of the plants in case of any changes while you are gone? I would stay with same strength of nutrients but would make 1 batch of 50% just in case as these plants will skyrocket when you do and you want to be present for it or only be gone a week at most.
You’ve done an incredible job with your plants. It really is easy once you get that first grow out of the way and you’ve built confidence in yourself.