The thirty meter band is such a "money band" for SOTA activations that it simply can't be ignored. Traditional end fed half waves either ignore it or put in a link to enable that band - e.g. the EndFedZ MountainTopper by LNR Precision (now Vibroplex).
It is possible to configure an end fed wire with two traps, one for 20m and the other for 30m. When finished, the inductive loading of the two traps shortens the antenna from 66 feet to 58 feet. The bandwidth for 20m covers the entire band. The band width for 40m is reduced but still perfectly acceptable within the CW portion of the band. There are losses associated with this trap - the combined losses from both traps is somewhere between 0.3 and 0.7 dB.
I used it during my activation of Grassy Ridge Bald W4C/EM-001 as documented by this YouTube video and it worked fantastically well with my LNR MTR4Bv2 and GM0EUL paddle.
Here is an image of the end fed half wave antenna. Only one trap is visible.
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