Now I have both my games at the same level I have been able to compare how two episodes played out on both my iPad and iPhone games, two unrelated and quite different logins.
Episodes were levels 5631 - 5660 as of Saturday 24th Feb 2024
To make it a fair comparison both games started on top win streak (2 colour bomb version) and used the same pre level boosters. Weekly win and Candy Collection provided timed starting boosters. Used these in both games for all levels and all three starting boosters for levels rated hard/super hard/nightmarish or legendary.
Findings:
It was a good day for crushing! I kept my top win streak through both episodes and only one level needed 10 gold to play on. Not one lollipop needed today! I had 15 mins UFOs from the weekly win but only used this twice and the timed boosters from the weekly win and candy collection came in very handy.
Comparison:
On every level one of the starting colour bombs was next to a striped candy or next to another colour bomb on the starting board! Half the combos were same type in both games, half equally good, but different.
Out of 30 levels:
17 played almost identically, often with a similar number of moves spare at the end.
8 played differently but with the same outcome (pass or fail)
5 played surprisingly differently. Two of them were unrated. Level 5645 was the most obvious difference: iphone got a lucky board and easy pass. iPad failed despite using a UFO and a stripe brush, had to play on for 5 extra moves.
The last level 1560 (nightmarishly hard) was an easy pass for iPad but iPhone failed, and I chose to lose win streak at this point. Failed on second attempt and then passed on third attempt with only the timed colour bomb as only booster.
Conclusion:
Most levels seem to be of the same gameplay and difficulty for both iPad and iPhone.
There are some notable exceptions, where levels play very differently and may lead to a fail or force the chosen player to pay gold to pass a level. But only about 6% of levels showed this, so it is probably part of King's "bespoke" approach of some specifically chosen levels for specific players
Using starting colour bombs and/or wrapped+striped was a winning strategy for both games and lead to lucky boards or strategic passes without need for further boosters. Warning: This applies to today and this level range only!