Claiming UK visitor visa - blank pages

[Kogutska]

Hi everyone,
I am seeking for the UK standard visitor visa (with the purpose of participating in conference).
There are two blank pages in passport. One is specially dedicated for visa stamps, the visa vignette issued by Czech Republic is on the other side of the list. Another one is for other notes, and also not blank on the other side (there are stamps).
Before making an application and appointment, I lead to the instruction on the uk.gov website saying that one blank page is required and sufficient. At submitting the application, the checklist of the documents for the appointment includes different requirement: "at least one page blank on both sides".
Could you please let me if anyone has an experience with such limited number of blank pages in passport? Could the application with page blank on one side be successful? Or should I replace the passport, however the application form is filled with the old passport data.
Thanks a lot in advance.

[Zerubbabel]

It's open to debate

What I heard is that they want either a page blank on both side or a side blank and the other one with just a stamp or two.

They don't fix a visa on a blank page that has already another visa on the other side. It's just for the immigration officers to be able to check the visa through a light without being disturbed by the security features of the other one.