This is just a warning message AFAIK. Everything is interpretted as it was in the past, but Checkscript is just trying to help.
The "if" statement that you show is fine...
And, your reseller correctly suggested using:
epsilon = 0.001
IF ABS(X-3') < epsilon THEN
for suitably small epsilon, instead of
IF X = 3' THEN
This will affect Imperial users the most, but Metric users are not immune. (While AC and GDL use metric internally: 1 = 1 meter, anything less than 1 meter is represented by a decimal fraction which is a potentially infinite binary number inside the computer, chopped off at the number of bits used for real numbers (representational error), and then when something like subtraction is performed, you get compounding of that error... hence the use of epsilon comparison such as above to account for such things.
Note, if X is a parameter and you want to know if the user typed exactly 3' (or a VALUE list etc resulted in that), then the epsilon comparison isn't needed, since 3' (as typed, converted and stored) = 3' (as typed, converted and stored). It is generally only an issue if some arithmetic has been performed.
One of the forum moderators • AC 25 USA and earlier • MacOS 11.6, iMac Pro