I've been using OpenMPT for a while now (about a year and a half!) and I love it, but this is one thing that's always bugged me. Is there a way I can set it up to enter effect/volume data "Famitracker-style"? That is, where the numbers are entered into the digits directly, allowing you to change a single digit in several effects in a row easily; rather than "pushing" the old numbers out, forcing you to type out both digits. This is really annoying, as I often want to change the speed OR depth of several vibrato effects (for instance) rather than having to retype out both digits for each one or copy-paste.
This is possible for command letters (hidden setting Pattern Editor.EditStepAppliesToCommands (https://wiki.openmpt.org/Manual:_Hidden_Settings#.5BPattern_Editor.5D) but not for parameters - one reason being that the parameter column is not split into two edit columns. However, most of the time OpenMPT has much faster means to do what you want: You can make a selection starting from the command you want to repeat and extend it to as many rows as you need, and then use the interpolation shortcut (Ctrl+K for the effect column by default). If you interpolate between a filled row and an empty row, the filled row's content is repeated in all lines inbetween.
Also, remember that Effect 00 in many effects mean, use the previous value, such as H00, J00, K00, D00. You then only need to alter one number rather than every one of them.
And also, pressing enter on a value will copy that number, pressing space will paste it into the current selected cell. Holding space can be used to quickly enter one number across a channel. Note: This may be different depending on your keyboard configuration