Hi Missa, have you considered seeking a feedee / weight gain enthusiast bbw or ssbbw who's actually into gaining weight for your clips? There's whole scene of ladies on clips4sale and similar places making weight gain fetish content but they don't have your special effects capabilities or film directing / editing skills.
To be honest, leaning that the models in your previous WG clips have found the fetish so personally abhorrent makes me unable to enjoy them any longer
but I am still glad you mentioned how your regular models feel about shooting this kind of content just for our weird pleasure. Please don't have anyone do anything they're totally freaked out by, we're not monsters! :O