just some tips:
guessing you made sure the rapid rooters are not over watered. to insure for faster root time (water logged cubes = longer root time). a way to prevent that is to water the cube. then shake it till it feels like its at an appropriate weight. in between fully watered and dry.
-nip water leaf tips to concentrate growth on roots. important growth in cloning is root growth, water leafs are part of the cycle to bring in new growth. important top growth comes from nodes and the terminal locations but wont occur until root growth comes.
-keep the lights on 24/7 and the dome closed fully. you do not have enough clones in that dome to have to worry about mold issues.
-every day open the lid up for 2 seconds and mist them with water.
-at day 7 in the dome. start using a regular plant veg feed at half strength in a mist bottle to promote faster roots. plants that dont have roots will take in food though the leafs until roots occur. plants take in co2 from the tops and oxygen from the roots.
lighting:
idk what kind of light you use. i recommend a T12 old school stoplight fixture with any bulb honestly. the 3200k or the 5500k will work fine for cloning, t12 fixtures are genital on plants and work great imo. t8 and t5 light fixtures are a bit to strong in my experiences. they can root clones, but they never gave me 100% on a clone dome vs 1 under a t12 (i feel the plant takes the t12 light easier)
temps:
-keep the temps of that dome around 75-80 degree. its cold out. you might need a heated temp mat to insure the plants do not chill during the night.
not really much other than that. i just stress starting to feed clones at day 7-10 because i know most all plants will start to concentrate there food from the greengage to the roots at those days. i mist them with plant food, then start feeding regular food at day 10. i expect them to clone, so im ready to feed them and not lock them out. rapid rooter cubes and most other cubes are hydroponic soiless mediums. they require specific ph and imo its important to start feeding it correct as a baby to insure future growth goes fast. if you dont feed the plant as it roots, it will yellow out indicating it rooted and is hungry.
best of luck, im sure you will do fine
-jake