For launching faster, the internal format of settings was changed. By increased number of symbol buttons, it had taken longer to process of loading settings. This process is modified to simplify and to accelerate.
New features by flicking are experimental. I guess that someone say these shall be by new buttons. But adding buttons may lead to mistakes of pressing buttons. By using each different operations, the mistakes can be reduced, I thoght... I can not decide yet. So this might change in the future.
About crashes, I had identified its direct causes, but root causes is not identified. As a tentative measure, SymbolsPanel displays a error message without crashes. When you get "Internal error" message, please report to me.