If CB's are about on a light IMC or VFR day, consider filing IFR even if you intend to remain in VMC as much as possible. Once you are in the system then CAS busts and navigation worries for deviations become much less of an issue.
I came back to Europe from Singapore two years ago and last summer was amazed by the level of CB activity down here in the centre. Not quite Singapore levels but heading towards it on some days.
This week we have already had a fair bit of convective activity and it is still only early May. To be honest this years annual I had storm scope fitted to back up the picture from the weather radar after a few hairy days last year.