It depends on your Direct Outs settings in the global settings menu. There are 4 options:
• Pre-insert (post-gain)
• Pre-fader (post-insert)
• Post-mute/solo (default)
In Post-fader or Post-mute/solo mode then the VU meters will display the levels that are being sent to the direct outs, so if you are not seeing clipping on the VUs, you should not be getting any clipping in the poly recording in those modes.
In the first 2 modes the signal is being sent to the direct outs before it hits the meters so they cannot show the levels. However you could use the Pre-fader (post insert) direct out setting then use the VU meters on EQ Master to check the levels on the insert chain.
Pro Tip - its always a good idea to use the gain adjustment settings (+/- 20dB) in the track menus for level balancing before you start moving any faders around - this way you can balance your signal levels and then just use the faders for mix levelling once signals are gain staged. This is particularly useful if you want to use the pre-insert direct out setting as this setting is post-gain. So if you have a hot signal coming into the mixer, you can take the gain down and see what it looks like on the VUs (with the fader at default 0dB position) to ensure you are not getting any clipping on that signal before you start mixing - if you do that then even using the pre-insert direct out setting should not lead to any clipped poly recordings.
Also worth bearing in mind is that MM track VUs are calibrated to 5V = 0db (as opposed to the Master track where 10V = 0dB in hard clip mode). This means that you have 6dB of built in headroom on tracks as clipping will not actually occur until a track VU hits +6dB (10V).
In the global settings menu of Poly recorder, you have the option to attenuate the inputs by -6, -12 or -24 dB which can also help with clipping issues.