someone wrote a tutorial describing how to batch edit a list of specific observations: https://forum.inaturalist.org/t/batch-updating-location-accuracy/11421. this seems like it would offer a way to do what you’re asking for.
i would offer an alternative to the steps 2 & 3 in the tutorial. instead of exporting a list of observations and filtering down that list, i would just produce a list of observation ids using an API request and a little parsing of the response.
for example, this (https://api.inaturalist.org/v1/observations?acc=false&user_id=robert_taylor&only_id=true&per_page=200) returns:
{"total_results":2640,"page":1,"per_page":200,"results":[{"id":73295636},{"id":73295635},{"id":73295615},{"id":71718871},{"id":71718870},{"id":71718867},{"id":71718866},{"id":71718865},{"id":71718864},{"id":71718863},{"id":71718862},{"id":71718858},{"id":71718857},{"id":71718854},{"id":71718852},{"id":71718850},{"id":71718849},{"id":71718848},{"id":71718846},{"id":71718845},{"id":71718844},{"id":71718843},{"id":71718836},{"id":71718835},{"id":71718832},{"id":71718831},{"id":71718829},{"id":71718826},{"id":71718825},{"id":71718823},{"id":71718822},{"id":71718821},{"id":71718819},{"id":71718816},{"id":71718815},{"id":71718814},{"id":71718812},{"id":71718811},{"id":71718809},{"id":71718807},{"id":71718806},{"id":71718805},{"id":71718803},{"id":71718802},{"id":71718800},{"id":71718799},{"id":71718795},{"id":71484833},{"id":71484831},{"id":71484829},{"id":71484828},{"id":71484827},{"id":71484826},{"id":71484824},{"id":71484823},{"id":71484820},{"id":71484819},{"id":71484817},{"id":71484815},{"id":71484812},{"id":71484811},{"id":71484810},{"id":71484809},{"id":71484808},{"id":71484805},{"id":71484804},{"id":71484803},{"id":71484800},{"id":71484799},{"id":71484796},{"id":71484795},{"id":71484793},{"id":71484791},{"id":71484790},{"id":71484789},{"id":71484788},{"id":71484787},{"id":71484786},{"id":71484783},{"id":71484779},{"id":71484778},{"id":71484774},{"id":71484773},{"id":71484771},{"id":71484768},{"id":71484767},{"id":71484766},{"id":71484764},{"id":71484763},{"id":71484762},{"id":71484758},{"id":71484756},{"id":71484755},{"id":71484754},{"id":71484753},{"id":70149533},{"id":70149528},{"id":70149526},{"id":70149524},{"id":70149523},{"id":70149522},{"id":69103029},{"id":69103016},{"id":69103000},{"id":69102998},{"id":69102997},{"id":69102991},{"id":69102986},{"id":69102982},{"id":69102979},{"id":69102975},{"id":69102969},{"id":69102961},{"id":69102950},{"id":69102947},{"id":69102944},{"id":69102937},{"id":69102929},{"id":69102923},{"id":69102918},{"id":69102910},{"id":69102895},{"id":69102888},{"id":69102882},{"id":69102880},{"id":69102870},{"id":69102866},{"id":69102862},{"id":69102833},{"id":69102817},{"id":69102816},{"id":69102815},{"id":69102813},{"id":69102812},{"id":69102808},{"id":69102807},{"id":69102806},{"id":69102801},{"id":69102800},{"id":69102799},{"id":69102798},{"id":69102797},{"id":69102796},{"id":69102795},{"id":69102793},{"id":69102792},{"id":69102789},{"id":69102787},{"id":69102785},{"id":69102782},{"id":69102780},{"id":69102779},{"id":69102777},{"id":69102775},{"id":69102772},{"id":69102771},{"id":66933588},{"id":66933586},{"id":66933585},{"id":66933584},{"id":66933583},{"id":66933582},{"id":66933581},{"id":66933580},{"id":66933579},{"id":66933578},{"id":66933577},{"id":66933576},{"id":66933574},{"id":66933573},{"id":66933572},{"id":66933570},{"id":66933569},{"id":66933566},{"id":66933562},{"id":66933561},{"id":66933560},{"id":66933559},{"id":66933558},{"id":66933557},{"id":66933556},{"id":66933555},{"id":66933554},{"id":66933553},{"id":66933552},{"id":66933549},{"id":66933548},{"id":66933547},{"id":66933544},{"id":66933543},{"id":66933542},{"id":66933541},{"id":66933540},{"id":66933539},{"id":66933538},{"id":66933537},{"id":66933536},{"id":66933535},{"id":66933534},{"id":66933533}]}
do a little find-and-replace, trim the beginning and end, and you get this:
73295636,73295635,73295615,71718871,71718870,71718867,71718866,71718865,71718864,71718863,71718862,71718858,71718857,71718854,71718852,71718850,71718849,71718848,71718846,71718845,71718844,71718843,71718836,71718835,71718832,71718831,71718829,71718826,71718825,71718823,71718822,71718821,71718819,71718816,71718815,71718814,71718812,71718811,71718809,71718807,71718806,71718805,71718803,71718802,71718800,71718799,71718795,71484833,71484831,71484829,71484828,71484827,71484826,71484824,71484823,71484820,71484819,71484817,71484815,71484812,71484811,71484810,71484809,71484808,71484805,71484804,71484803,71484800,71484799,71484796,71484795,71484793,71484791,71484790,71484789,71484788,71484787,71484786,71484783,71484779,71484778,71484774,71484773,71484771,71484768,71484767,71484766,71484764,71484763,71484762,71484758,71484756,71484755,71484754,71484753,70149533,70149528,70149526,70149524,70149523,70149522,69103029,69103016,69103000,69102998,69102997,69102991,69102986,69102982,69102979,69102975,69102969,69102961,69102950,69102947,69102944,69102937,69102929,69102923,69102918,69102910,69102895,69102888,69102882,69102880,69102870,69102866,69102862,69102833,69102817,69102816,69102815,69102813,69102812,69102808,69102807,69102806,69102801,69102800,69102799,69102798,69102797,69102796,69102795,69102793,69102792,69102789,69102787,69102785,69102782,69102780,69102779,69102777,69102775,69102772,69102771,66933588,66933586,66933585,66933584,66933583,66933582,66933581,66933580,66933579,66933578,66933577,66933576,66933574,66933573,66933572,66933570,66933569,66933566,66933562,66933561,66933560,66933559,66933558,66933557,66933556,66933555,66933554,66933553,66933552,66933549,66933548,66933547,66933544,66933543,66933542,66933541,66933540,66933539,66933538,66933537,66933536,66933535,66933534,66933533