you cant have it all, i know what you mean. mule mode. that is hardly possible with *any* modern flashlight (name me 10 models!); it's possible though for the Romisen RC-29 & RC-G2 which i had reviewed on BLF.
it is still possible to disassemble the Xeno E03 V3, as was mentioned on BLF in the Xeno E03 thread.
candle mode? simply put a Fenix LD20 diffuser tip (the white one, or the transparent one) on top or the original Xeno diffuser cap ;)
the distance between the holes differs. we can tell with the naked eye and your linked webpages. the Fenix clip is already a perfect and very professional clip and a satisfactory solution. other clips might exist, have you checked CPF? ( i own the Fenix clip, and i use it for the Romisen RC-29 too! )