Really is worth investing in a set of metric and imperial hex/Allen keys, even a top quality kit of long keys in a good case won't be much more than the cost of the Fender tool (in fact a lot cheaper for example https://www.screwfix.com/p/magnusson-metric-imperial-hex-key-set-30-pieces/3305V?tc=EC5&gclsrc=aw.ds&gad_source=1&gad_campaignid=21550393591&gbraid=0AAAAAD8IdPwPTrbujmZZ3pxHZxxUweXDB&gclid=EAIaIQobChMI9sKP6dD2kQMV4J2DBx2wPSjuEAQYASABEgLzufD_BwE), and that way when you come across a non-conventional size (e.g., Warmoth and Allparts necks, Badass bridges etc) you're covered 👍