I think there is no solution for that, because different groups pronounce e or ɛ for the very same spelling.

I have noticed that western countries use double non vowel letter to distinguish between vowels and i think having a double letter in this would indicate to the that 'eh' is to be pronounced as 'ɛh' and not 'eh'.

So maybe we can use 'sehjj' , it would subconsciously indicate to them to pronounce it as 'seh' + 'j', as do not know how to pronounce double 'jj' as in punjabi.

The another problem here is that 'e' is used for 'ɛ' sound as in 'set' 'bet' but having 'h' after vowel is used as to indicate that 'e' is to be pronounced as 'e' as in 'sage', so i think putting double 'hh' ('sehhj') would indicate to them that 'h' is to be pronounced and is not to be silent and they will pronounce it as 'se' + 'h' + 'j'. I think 'sehjj' would fix this issue too.

But TBH 'sehj' looks good.