Hi just looking on advice on hanging a pull up bar, I am hoping to hang it over a garage door because of head height but was wondering is it safe to hang upside down It's got 9 bolts either side and I was thinking if drilling a couple through the wall for extra support Gravity Fitness Heavy Duty Wall Mounted Pull Up Bar for Calisthenics, Cross Fit, Commercial or Home Gym https://www.amazon.co.uk/dp/B01EYWVCSI/ref=cm_sw_r_u_apa_i_otXOFbHVHR91B?_encoding=UTF8&psc=1