Brackets in Calculated Items

[CyberJacob]

I have several items that I'm trying to combine for a trigger, and am using a calculated item to handle some of the processing. One of the items stores the last time a process ran:

system.run[powershell -c "(curl x://xxx/api/a/{#ID} -Method POST -UseBasicParsing -Body @{key='xxx'}).Content", wait]

And another contains the maximum acceptable delay:

system.run[powershell -c "(curl x://xxx/api/b/{#ID} -Method POST -UseBasicParsing -Body @{key='xxx'}).Content", wait]

I am then trying to combine these using the following formula:

fuzzytime(system.run[powershell -c "(curl x://xxx/api/a/{#ID} -Method POST -UseBasicParsing -Body @{key='xxx'}).Content", wait]",last(system.run[powershell -c "(curl x://xxx/api/b/{#ID} -Method POST -UseBasicParsing -Body @{key='xxx'}).Content", wait], 0))

However, I cannot find a combination of backslashes to escape the key that does not cut off the ").Content..." on each one. Is it possible to escape brackets in a calculated item formula?

For reference, the error I'm getting is as follows:

Cannot evaluate function "fuzzytime()": item "x:
"system.run[powershell -c "(curl x://xxx/api/a/{#ID} -Method POST -UseBasicParsing -Body @{key='xxx'}" does not exist.

Thanks