Well, I've quite successfully ridden home (and finished races) with significantly dented sewup rims. Hit a puddle disguised deep pothole in mid-winter Michigan with LowRider panniers loaded with books. A full 1" deep indent. Bump bump bump home. Collapsed a GP4 with 17k lava dust miles and no remaining sidewall on a routine crack. Roughly the same indent and 15 miles home. (A newspaper could have been read through the missing sidewall with not a lot of difficulty. A clincher would have died violent death years before.)

The race incident was a lot less significant. A very fast 4 hour race that started two hours late. I'd kept my tires soft-ish to not hammer me on the poor roads of the late 12 mile stretch where the race was going to be won or lost. Two hours after I thought I'd be finished and showered, I simply did not have enough air to make it over the RR tracks 1 mile before the finish. Dented both rims significantly but being old-school 1970s aluminum, both not an issue except for the noticeable bump and easy to pull straight enough to finish the year as race wheels. And I placed in the finish. Those dents made no difference at all.

My training wheels had Arc en Ciel rims. Light for training but good for club races and good enough to be back-up wheels at races. New England roads took their toll. By fall they were so far from round and straight I automatically re-built them over winter with new rims. But all these wheels were for tubular tires. Never a rim to tire fit issue. Well glued tubulars simply didn't care how round or dented the rim was. I also rode cheap 400gm tubular rims on my fix gear that got year 'round service. Those rims were free-form polygons by March. (I loved the MAFAC Racer brakes that were so forgiving stopping on those totally trashed rims. Clinchers are different animals. Higher standards of operation ore required!